The effect of having Andrew Bynum back is a real bonus for the Lakers. I've had many an experience on the basketball court where picking up a big man bumps everyone down a spot. In this case, Gasol goes to the four, Odom the three. This allows both men to comfortably play in their natural roles.
I think he will have a great effect on the team and they may be able to make a run for a number of years at the Championship.
I also don't think the Celtics will be able to win as many games because so much of their game depended defensive intensity, which is difficult for multi-millionaires to muster on a consistent basis once the "newness" factor wears off.