This is the problem with expansions; they eventually stretch an MMO out to in crazy directions and, unless you keep up and never take a break, it is easy to feel left behind or to ask when enough is enough?
This is a factor that keeps me from going back to MMOs. When you log in and see three expansions’ worth of change, do you say, “Oh boy, it’s like a whole new game to learn!” or “Oh crap, it’s like a whole new game to learn!” The game you played before is gone, you need to relearn at least half your character’s skills and all the mechanics, every piece of loot you ever acquired is now vendor trash, and the population center is 20+ levels thataway. Welcome back!
What MMO does well in welcoming back players who have been gone for more than a year?