I really enjoyed it.
A lot of people complained that it wasn't exactly the same as Skyrim but multiplayer.
I didn't go in expecting that, and I was happy with my adventure. Lots of exploration (once you get past the newbie stuff, of course), boatloads of lore, fun combat (at least early on, I suppose any combat could get boring), and a decent skill system. I liked that there wasn't any BS about gathering stuff like needing a particular skill or consumable object. You get your own nodes of everything, loot is instanced per player, etc.
I had a really great time, even running around in the same newbie zone with a hundred other players.
I pre-ordered mine today (along with Thief 4).