At first it seemed a lot like Warcraft. Some of the conventions are the same, which makes the transition pretty easy. But once you get past the obvious similarities, things start to get really interesting.
I've been playing a Disciple of Kain, which is a melee-based healer class. I wasn't too certain about it at first, but once I got used to the idea of healing allies by stabbing enemies I started to really like it.
So we found ourselves at the base of a hill, and at its top was a keep defended by dwarves and a handful of Order players. Order are the good guys. We are the bad guys. We wanted their keep.
You don't stop for mana in War. It was a half hour of non-stop castle siege, complete with player-operated balistas, catapults and boiling oil.
When it was over, the keep was ours.
That was the most fun I've had doing anything in a long time.