Came out today. I played the demo, which felt a lot like a mix between Fable and Skyrim. It wasn't quite as open-world as Skyrim, but still pretty open, and with a cartoon-ish art style reminiscent of WoW/Fable.
The largest appeal is the class system, however. You have a talent tree system, with the three trees being, essentially, Warrior/Rogue/Mage. You can be a pure one of any of the three, and you get a class assigned based on that. But if you start putting points into other trees as a hybrid, then you unlock a new class based on how you've spent them. It's pretty cool. And you can switch between any of your unlocked classes, which is handy since a lot of them have unique bonuses.
The big bonus to playing the demo is that if you decide you like it, then all the stuff you earned carries over to the main game if you buy it. So you don't have to do the tutorial section again.
Haven't bought it yet, but I think I might, and I was seeing if anyone else was going to.