I'd be hugely surprised if it turns out to be directly related to his concussion (my best guess would be heart problems for some reason or another) but no matter what the cause, it's pretty messed up and sad.
From all accounts he was a great person and good guy to be around and losing those people is a sad thing
He definitely seemed pretty genuine in the Garden of Dreams events shown during pre-games.
such a shame. from everything i read about him, he seemed to have a good head on his shoulders, was a good teammate and seemed to be active in the community. if this is related to his head trauma this is really going to force the nhl to reevaluate how it treats fights and increase the regulations about players after concussions. my thoughts go out to his family and friends.