Not sure if it was the hit itself that was vicious, but the impact with the glass reminded me a lot of the luger that was killed at the olympics last year. The guy never saw it coming and its almost like Chara just happen to hit him in the wrong place at the wrong time. It looked like Chara was trying to drive him into the bench, but he got to him a split second too late and they missed the bench and hit the glass.
I know that there have been some complaints recently with Crosby being out for months and this Gillies guy from the Islanders being suspended 19 out of the last 20 games, but this one just seems to be a freak accident unless Chara intentionally knew he was driving this guys face into the side of the glass. What I'm trying to say is that the glass part was an accident, but the preceding hit wasn't.
I never understood the excessive violence that is permitted in hockey, but not in any other sport. Sure the NFL has body on body contact, but guys get ejected if they make any type of a punching motion. Baseball has pitchers that are head hunters, but they usually just send a warning sign with a pitch into the meaty part of the body. Basketball had its own problems after the Ron Artest melee and just this year started handing out technical fouls to anyone who even complains to the refs. Hockey seems to police itself the worst among the 4 sports as even suspensions don't end most disputes.
Now I don't watch any hockey other than a few playoff games and the highlights on Sportscenter so I don't know if there was any bad blood from previous games, but even with that in mind I don't think the ultimate result was Chara's intent.