Myst Online - Previews @ 1Up, Ten Ton Hammer

Myst Online has been previewed at 1Up in a short article that doesn't really reveal much about the gameplay:

In less than a week, the long hard road to The Cleft will finally lead to its destination. Originally laid to rest in 2004 due to low subscription rates, the online portion of Uru: Ages Beyond Myst was one of the more ambitious online titles of its time, melding elements of the classic point-and-click adventure series with the concept of the metaverse -- the virtual world that replaces the internet as penned by Neil Stephenson in the novel Snow Crash. Even today, the game, now known as Myst Online: Uru Live, is still one of the most novel, not to mention intriguing, games in this "World of Warcraft" that we live in. There is no loot to score, nor are there dragons to down, but the satisfaction felt in unraveling the mystery of the D'Ni rivals that of any hack-and-grind around.

Meanwhile, Ten Ton Hammer takes a more detailed approach:

Make no mistake, this is an explorers’ and a socializers’ MMO – those who need constant scoreboarding to get their achievement fix should stick this game out for at least an hour to see the virtues of a purely cooperative, non-combat MMO. Maybe it’s not your gaming cup of tea 100% of the time (as part of the Gametap fold, it doesn't have to be), but few will disagree that Myst Online is one heck of a beautiful, brain-expanding escape from the grind. Gametap is a perfect home for Myst Online emphatically not because the community is so niche, but because the barriers to entry are so low. Myst Online is a good reason to check out Gametap, and Gametap is a good reason to check out Myst Online. While it doesn’t have quite the broad appeal of "Sam and Max", Turner seems to have scored themselves a brand building win-win with Myst Online: Uru Live.