I've only played the demo for half an hour now, but am liking it very much.
I very much like the character customization-options you get. Sure, you only have choices in 3 different categories: face, hair (including beards) and body-size. But hell who really needs the myriad of options you get in Dragon Age with thousands of sliders, when you can get a dozen very well designed (and very pretty) faces and hair-styles for each archetype?
What I also liked is how the game seems deeper rooted in the 'The Dark Eye' lore. At least judging from the bit I've played.
Already heard hints about the Flussvater (the river-father), the Khom-War, the Batlle of the 1000 Ogres, the curse on Thorwalians relating to the Big River. Really cool if your a TDE nerd

All these little things, I really like it.
Also read somewhere that the game's story will be somewhat integrated with the (second) reissue of the Phileasson Campaign. Awesome.
The two new character-classes are also cool, although you can only choose one of them in the Demo (the Gjalska Tribal Warrior), the other one being the Geode (a kind of dwarven druid). Hoping they'll include human druids and witches in the next installment, they could make up a group of nature-casters in the char-selection.
Whats also really nice is that one of your party members aparrently is a Phex-priest, although I think he only has 4 different liturgies (priest-spells). Still cool.
Don't know if I'll play any further in the demo though or if I'll just wait till february. This way I won't have to play through the beginning again.