According to Bruins coach Claude Julien, Aaron Ward might have suffered a broken orbital bone when he was sucker-punched by Scott Walker at 17:13 of the third period. [Link]
Update (4:10pm): According to Canes Now Walker will not be suspended for the punch, but will be fined $2,500. It was expected that Walker would be suspended at least one game because of the fact that he received an instigator penalty with less than five minutes remaining in the game and in those circumstances a one game suspension is automatic. However, the NHL rescinded that one game suspension. I'm very surprised based on the way the NHL is run nowadays that they decided to rescind that one game suspension. I personally thought that it was a sucker punch, but I actually don't like the stupid instigator rule, so for the first time in a while I'm happy with the NHL's punishment under the circumstances.