I agree JohnC, Buffalo has to get better on D. You can definitely see the impact that defensemen that can move the puck have in the NHL playoffs. Nashville is just fantastic when it comes to clearing the zone and moving the puck. And who knows, maybe their defensive coach may be coaching in Buffalo soon...
I think they almost have to make a run at Shattenkirk in FA.
Just think how different the top-5 D could look next season if it includes Risto, Shatty, McCabe, Antipin, and Guhle.
As I've said though, Shattenkirk will be the prize of all FA prizes, so I'd probably be prepared to settle for Karl Alzner as a consolation. More of a 2nd/3rd pair guy, but solid.