I have yet to be dissapointed by a Blizzard game, and if they decide to incorperate a PvP server (horde vs alliance) I will definatly be there, because Sony has yet to fix any of the various issues with their many failed PvP servers, where all my characters happen to be.
As for Everquest 2, I kind of see a lot of people trying it, but most people just comming back to the original game, I guess it will depend on how it goes, however, and a lot of different things. Personally, however, I would rather stick with the original than move on. I have more reasons for this than anyone would care to read, and most of them are merely personal preferance, so I won't list them all.
It will be interesting to see. So far place my bet as WoW > EQ > EQ2. We shall see...