I agree that taking a break from the game can be a very big help.

I think that persistent-world MMOs change the way we approach gaming, and are designed (not deliberately, IMO) to induce burnout. I cannot recall any other video game that I would play almost every day for at least an hour a day for months, even YEARS, at a time. There were periods during my EQ and early WOW days where I was playing every day, two-to-four hours a day, for weeks on end.

Even games like the Civilization series, which I would play an absurd amount of over a short time, didn't keep me coming back every day for hours at a time over a course of months. Or even weeks. I played a shitload of Civ2, and more than a few of my Civ2 sessions were almost certainly much longer than my longest ever WOW/EQ session. But since each game finishes at some point, I'd go for days or weeks before I picked it up again. Not my MMORPGs, though. Day in, day out, grind grind grind. It was fun, don't get me wrong. But burnout is inescapable, IMO.

So now I take breaks whenever I feel I need one. Or I do as I am doing now, where I play 30-60 minutes at a time with the occasional day off and the rare 2+ hour play session. I don't think I've logged into WOW in three days or so as of today, and I'm not worried about it. And these days when I play, I don't feel as if I'm falling behind and need to make up the slack, either. So the threat of burnout is pretty much gone now and I can enjoy it more when I play.