My prediction is that D Lee is going to be next year's Beltre - but not as dramatic.
He will regress, and he will be a .280-.285 hitter again, which means corresponding drops in power and on-base, since he won't be getting walked as much. People have already pointed out his regression in the second half of this season. It's already begun.
Unlike Beltre, though, he won't be virtually worthless next year. He'll have value - it's not like .280 with 35 HRs and 100+ RBI is bad - but he won't have the Pujols-like value that he had this year.
Too bad for Lee that this wasn't his contract year. He could have cashed in pre-regression like Beltre did.