The main thing that keeps me coming back is the people I play with. Now that some of them have cut back on some of their play, I have also. It's fun to enjoy good guild chat as you're leveling.
I do like that the game is a bit more difficult with the low levels hurting you now, but I've gotten so spoiled or lazy that it irks me. lol If that makes sense at all
I also like the leveling system. I'm always up for reaching a goal