Kelly is an underrated role player for Ottawa so this is a key signing. One of the best penalty killers in the NHL, IMO. He could be a team leader in a few seasons if he sticks around long enough. He'll do it all (grind, fight, etc) when he has to and he's one of my favorite Senators for sure.
On a semi-unrelated note, I've never quite understood his intermittent visor usage, but it's always amusing to try to guess how many games he'll decide to wear it in the season versus not wear it (Redden is kind of like that too). A tad odd, but amusing nonetheless.