One thing to keep in mind when comparing winning a Super Bowl vs winning an NBA championship.
The one game factor vs a best of seven series factor.
The best team always wins the NBA championship.
The best team does not always win the Super Bowl because of the any given Sunday factor. Football is an odd game of matchups, bounces, referee calls, and rules that benefit one team and screw the other. The Patriots were screwed by the Helmet catch where the ball clearly hit the ground and it never get a review. 4 plays later, I had a stroke (well not really but my wife wanted to rush me to the hospital).
The Celtics proved they were the best team out there last year and they have thankfully improved on that. They just need the energy and health to find 16 wins between Tax Day 2009 and July 4th, 2009. BTW Cleveland and LAL is pushing awful hard for victories this year.