I had never seen some Finals before where there is really no clear favorite for the MVP trophy. For the Lakers I would say it's Gasol followed by Fisher (I'm sorry I wouldn't put Kobe on the list, the guy is jacking up shots like Monta Ellis, sure he made a lot of them last night but he is playing right into the C's gameplan).
For the Celtics... wow, I have no clue! I would say Rondo for "consistency" because he was huge in game 2, OK in game 3, but bad in games 4 and 1. Ray had 1 great game, 1 terrible one (game 3), 1 subpar one (game 4 but he was huge in the 4th), same for KG and Pierce... tough to say.
And yes, Baby has been huge in every game (and Sheed)!
The thing is, I'm not even sure we will have a guy who steps in as the favorite for MVP in the next two games because this team simply plays collective basketball and rarely has the same leading scorer or "impacter". But overall I would say Rondo, especially if he has one other great game.