Giant Bomb has sone a quick look for this game. In it, Brad and and Dan from Giant Bomb play the game for a little bit and comment on it. You can view it here.

Game Informer has written a review with a score of  7.25/10 for this game. A quote from the conclusion:

Magicka 2 delivers more of the magi-mayhem that the series has become known for, but doesn't really take things in any new or particularly interesting directions. If you enjoyed the first game you will probably enjoy this new journey. 

Magicka has always been far more action game than RPG and adding PvP arguably takes it further from our realm but for those who have followed it, PC Gamer has a preview of the upcoming PvP patch.

An interesting contrast to GameSpot's criticism, Hooked Gamers has awarded 9.5/10 to Magicka: Vietnam.

Magicka is a rare gem in a world filled with boring FPS games that use the same recycled storyline and formula and the Vietnam DLC is there to extend the fun no end. Whether you'll be playing it solo or better yet, with a group of budding magic slingers, Magicka: Vietnam will please anyone who is a fan of the original game. For such a low price, it is hard not to give such praise to this pint sized DLC that keeps the spirit of the original alive with its luscious humor, numerous pop-culture references and unique gameplay style that many have fallen in love with since it's release. If you still have the itch for fireball slinging fun, go out and get Magicka: Vietnam. You will not be disappointed.

GameSpot has reviewed the Vietnam expansion to Magicka. The score is a lowly 5.5/10 mostly because of extreme difficulty:

Vlad and his cowled little buddy are off to the jungle in Magicka: Vietnam, a downloadable content pack that shifts the arcane action of Magicka to a fantasy-styled Southeast Asia. It goes without saying that this is a decidedly goofy premise for a role-playing game that is all about casting spells and killing fantasy foes. However, the notion of a wizard heading off to fight the Viet Cong somehow seems appropriate here given the anything-goes nature of the original game. Unfortunately, the oddball nature of the add-on is its biggest plus. The idea of running through the jungle blowing up orcs and trolls is a lot more appealing than the reality, as the lovable melee mayhem of the original combat has been replaced by frustrating difficulty and some odd design decisions. 

Magicka: Vietnam has been released:

GOOD MORNING, MAGICKA!

Magicka: Vietnam Invades Digital Retail Shelves Everywhere
Launch Trailer Released, No Embedded Journalists Hurt

NEW YORK – April 12, 2011 – I love the smell of Magicka in the morning. The whimsical wizards of Paradox Interactive and Arrowhead Game Studios today announced the deployment of Magicka: Vietnam, the DLC for action-adventure game Magicka. The DLC Magicka: Vietnam for the friendly fire-filled indie hit is now available on all leading digital distribution platforms for $4.99.

To check out smuggled footage of the game, check out the launch trailer at:
http://www.youtube.com/watch?v=rxeApMy3Rdo

Answer the call of duty to take up arms against the Goblin-Cong, trudging through a napalm-scorched battlefield with a bad company of up to four wizard GIs, and earn new medals of honor and achievements as you eliminate scores of enemies with not-so-wizardly machine guns and a new napalm Magick, liberate prisoners from POW camps, and escape to a Huey before it gets shot down by a pistol—all of this, of course, in your stylish robe fatigues and hood-friendly helmet.

In commemoration of the Magicka: Vietnam launch, Magicka will be discounted on several digital download portals, allowing players to snatch up the acclaimed title for up to 50% off—including bundles and 4Packs. So be on the look out for Special Promotions for Magicka!
The deals will magickally appear here: http://www.paradoxplaza.com/deals

Magicka: Vietnam features:

• Vietnam themed game world with a twist
• 2 Challenge maps (1 scenario challenge & 1 survival challenge)
• New Vietnam themed enemies
• Many new Vietnam era weapons
• Stylish GI Wizard robe
• New Magick – Napalm strike
• Innovative and dynamic spell casting system with thousands of possible
  combinations
• Up to four player co-op in all game modes as well as single player option

Experience the parody and satire of a cliché fantasy world/jungle war

Blue's has news that Magicka: Vietnam is expected on April 12 and they also have the first screens.

They're a zany bunch at Arrowhead. The first expansion to Magicka has been announced at GDC - Magicka: Vietnam. 

Paradox Interactive Unveils Magicka: Vietnam at GDC 2011

Didn’t See That One Coming, Did You?

SAN FRANCISCO - March 1, 2011
The wizards of Arrowhead Studios have whipped up something special for all the Magicka fans out there, today revealing the first expansion for the definitive “blow-up-your-friend” simulator that has taken the fantasy world by meteor storm. Magicka: Vietnam (yes, you read that right) will soon be available on all major digital distribution channels.

Have you ever wondered what it would have been like if wizards were allowed to roam the jungles of war-torn Vietnam, attempting to bring peace and stability to the region by casting spells on all opponents? Wait, you haven’t ever wondered that? Ever? Okay, so we’re probably the only ones who have but in our defense: here’s your chance to stop being so closed-minded. Magicka: Vietnam delivers over-the-top action as players take on the role of four meek and physically inept wizards as they try to do what so many 80’s action stars have done in the past: blow stuff up.

View the Magicka: Vietnam Announcement Trailer here: http://www.youtube.com/watch?v=cs2DsoiA54Y

Accidentally blow yourself to bits by playing the Magicka demo on Steam: http://store.steampowered.com/app/42910/

For the latest news on Magicka:

Web page: http://www.magickagame.com 
Facebook: http://www.facebook.com/MagickaGame 
Twitter: http://twitter.com/Magickagame 
Forum: http://para.do/hsdbzG

People are sending in Magicka articles, so I guess we'll pick up coverage even though its not an RPG.  First, Melvil noticed a video review at GameTrailers with a score of 8.5/10. 

I thought I'd add a couple more via Blue's. YouGamers awards 87%:

Different elements can be combined into multi-element spells or you can apply multiple copies of the same element to increase the strength of that element in a spell. Up to five components per spell, ten different elements and four possible target modifiers equals thousands of theoretical combinations. While most of these are just slightly modified or strengthened versions of base spells, there are still hundreds of functionally different spells you can cast. For example...

Elements also work logically - some are polar opposites that cancel each other out (or merge into another element) and some are hazardous to mix together. Spells are also equally hazardous to everything they hit so that nice combo of freezing wet targets is very effective, but it also applies to you - cue hilarity and "accidents" in up to 4-player co-op mode. Yes, Magicka can be played alone just fine but the spellcasting system truly blooms in co-op, especially as friendly fire is not an option you can disable and as multiple spells can be combined even more effectively with multiple wizards working together.

...and Out of Eight says 6/8:

Magicka takes a really neat idea, making your own spells in real time, and runs with it, almost to the top. It is quite fun banging out spells on your keyboard, using up to five elements from a list of ten, and then using them on enemies, yourself, your weapons, or the adjacent area. The results are some nice, somewhat open-ended combinations, producing sprays, beams, projectiles, shields, and other assorted chaos. While destroying an enemy with a beam rather than a projectile essentially accomplishes the same task, making the spell creation options a bit extraneous (not to mention tedious), there are some enemies that are more susceptible to certain elements so there can be the occasional tactical decision on which element to use. There are some advanced spell combinations that are either learned by accident or spelled out in books you discover during the campaign, but there are relatively few of these to choose from. You aren’t restricted by mana and don’t need to level up to cast better spells: everything is available from the beginning and you can throw out bolts and healing buffs as often as you’d like. This, of course, can lead to a lot of spell spam, just throwing out the same combination over and over again, which takes some of the fun out of it. It also takes a lot of time and energy simply casting spells, since you must tap out the correct combination every time; sometimes I yearned for the more restricted but less tedious method of simply pressing one button to cast a spell. The game is fantastic in cooperative multiplayer, where you and up to three of your friends cast spells together; since friendly fire is always on, you need to be careful about where you aim and when you use area spells. This is how the game is supposed to be played: there are too many enemies to deal with by yourself, and the game fails to adjust the difficulty based on how many human players there are. You must also complete an entire level in one sitting and can’t save your progress wherever you’d like; this wouldn’t be as significant of a limitation if Magicka gave you more frequent checkpoints, placed after every battle. The adventure mode lasts long enough, and finding players is easier now that the initial multiplayer issues have been sorted out. Despite some limitations, for $10, fans of action role-playing games can’t go wrong.

We haven't really been following Magicka, the Gauntlet-styled mage action game, but for those interested Sir_Brennus writes that a German retail release is planned by Deep Silver for February 25th.

Shack says Magicka was revealed last year but I don't remember it.  A teaser trailer for this action/RPG from Arrowhead Game Studios, being published by Paradox, has been released.  A sense of humour and 4-way co-op seem the big draw cards.