He stated repeatedly that he wanted to finish his career as a Bruin.
I'm sure the contract is front-loaded so that he gets most of the money in the 1st 4-5 years, then he can retire having gotten most of the money in the contract. If he retires, the money comes off the books for the Bruins. It's a win-win. Savard gets his money, the Bruins have flexibility to add more pieces to the puzzle over the next few years.
Edit: According to nhlnumbers.com, his annual salaries for the extension are as follows:
2010-11 $7M
2011-12 $7M
2012-13 $6.5M
2013-14 $5M
2014-15 $1.5M
2015-16 $525K
2016-17 $525K
Anyone think he'll still be playing in 2015 (when he'll be 37)?