Well, Planetside still is around, but it's more of a dead horse along the lines of every other mmo that's lingering around and really shouldn't be. It's only still around because there's nothing else like it to compare to. And with Global Agenda around the corner, that should change.
If Global Agenda fails me then I'm pretty much done bothering with MMO's ever again.
Warhammer is still being played by me, but only as a time-waster and to hang out with in-game friends until Global Agenda comes out or I get into beta.
None of these games people have listed are "fun" anymore, and I think the developers forgot what fun really means. They patch games in an attempt to keep it alive, but it just fuels the exodus. And they rarely take into account how the community adapts their games to actually make them fun for themselves, and then proceed to kick it over like a sandcastle that doesn't belong (like forum-organized duels in Warhammer being considered illegal and reportable offenses).
Mythic and Blizzard think exactly the same and honestly believe that constant waves of new content, rather than bug-fixes or game balance, is what people want. I'm just surprised WoW is still around, being the steaming pile that it is, still garnering the huge amounts of praise as if it's been original in any way since launch. Add in any other mmo that's come out after EQ, UO, or DaoC, to that as well.