I played the US beta for a bit, got to a L26 Orc Warlock, then found it a bit too samey.  The quests are all talk to this guy, take item here/kill something/fetch item(s), return to quest originator/don't return/go talk to someone else.  Becomes a bit of a chore.
The PvP isn't that great either, I much preferred the PvP battle structure in Guild Wars when I was playing the beta of that.  Furthermore, whereas in something like Planetside you actually had to have some aim to be good in battle, in this you don't, but the games are slightly different I guess.
Don't get me wrong, I had a lot of fun playing WoW, but it seemed like I got to a point when I wondered what I was actually playing for any more apart from level grinding... and perhaps (in retail) eBay fodder
