Granted I'm thinking more of our little world than the big picture, but I'd think the Shins might have a shot at band of the decade.
They pretty much went from indie buzzband to getting their name into a largely distributed move to having an album break the billboard top 10...and all on an indie label. They also seem like the poster children for the new "Indie is the New Mainstream."
If they play their cards right, and the next album takes off, I think that argument could be made.