Deals I've seen mentioned:
At Best Buy, if you're in the Reward Zone Gamer's Club you get a $10 gift card with purchase and coupon. You can also get $10 off a Madden Xbox Live Gold 12+1 subscription card if you buy it with Madden 2010.
At MicroCenter(I think?), if you reserved the game this weekend, you received a coupon for $25 off(360 only).
At Target, it was part of the reserve for $1, receive a free $5 gift card when you pick up your reservation. Also, they have a deal if you buy it and 60GB Xbox 360.
At Gamestop, you get a full demo(code for download) of the Super Bowl when your reserve it. Also, if you trade NCAA 2010 towards it, you receive $40 credit.
I'm sure there are more, but that's all I can remember at this point.