I'm in the midst of some burnout myself. But I'm sure that, after a few weeks, I'll pick it up again and continue my obsession.
My advice is to create a story, and roleplay your character. It extends the longevity of the game by thousands of hours - at least for me - and many of my characters reach the point where I can continue their story without touching the game. I become so involved in their lives that I can write about them and their lives after the events of the game.
If roleplaying isn't your thing, then perhaps you're starting to reach some extended burnout - you're getting tired of the content. That's a natural thing in gaming, and I don't think there's much you can do about it, short of buying any DLC you haven't already. I you feel like you've explored every inch of the world and just don't want to anymore, why not pick up Oblivion of Morrowind?
Why not do something productive instead of trying to insult me and fail miserably? Kthanks. You don't know me, kid.
Actually, that 'kid' just made some good points. It's basically an abbreviated way of saying what many others are suggesting.