I feel like an underrated aspect of this signing is just the veteran presence that he will add on this team. Say what you want about his skills, diminished or not, he's an experienced player with proven playoff success coming aboard with a young team. In terms of our forward lines, other than Moen, Gionta and Plekanec, you're looking at quite limited playoff exposure and just general experience in the league. Add to that that Briere has had an exemplary work ethic throughout his career, and he knows the ropes as a diminutive forward in this league on a roster full of younger, similar players, and you're looking at a wealth of knowledge to be spread throughout the roster.
I'm not saying I love the move, but it's asset management. The contract isn't crippling. He is a legit NHLer (who may or may not be deserving of the contract he's signed to) and he didn't cost anything other than salary cap space. Yes we need to get bigger. But those options are all but exhausted at this point for this season, so let's bridge the gap with a player that seems to want to be here, and fulfills also a marketing need (big name, although over the hill, french canadian).