Justin's updated his total value numbers through the games of September 5th. If you're not familiar with these numbers, you should be. They're the best, Jerry, the best -- better than VORP and way better than WARP.
He starts with custom linear weights on offense, adjusts for ballpark and league, and converts to runs above replacement level. He then adds a position adjustment based on position difficulty, not offensive-averages by position. Finally, he addresses fielding at each position with an average of STATS and BIS zone ratings converted to runs. (You can read about the full methodology in these posts.) MLB leaders::
Albert Pujols and Grady Sizemore have been significantly better than anyone in their respective leagues. Of players on teams in playoff races, Chase Utley and Dustin Pedroia are leading the way. And I have a feeling I'll be writing about Brian Giles' and Joe Mauer's underrated seasons soon.
(And no, Justin's offensive ratings don't include anything context dependent like performance in the clutch. So depending on your definition of MVP, it might not be the best offensive stat to use for that discussion. But the defensive numbers are still useful.)