This is a pretty vicous hit and then some, via We All Bleed Red on YouTube (with both feeds):

From NHL.com:

Minnesota forward Cal Clutterbuck had to be helped off the ice late in the third period of Thursday's 3-1 victory at Edmonton with what appeared to be an injured left leg. Edmonton's Taylor Hall received a five-minute major for kneeing and a game misconduct for his center-ice hit on Clutterbuck with 2:33 remaining in regulation. The two collided in the neutral zone; Clutterbuck was helped off the ice and was unable to put any weight on the leg.

"I really didn't feel like it was knee-on-knee at all," Hall said. "I thought I got him with hip or torso area. It was a weird play. It [stinks] to see him down, but I don't think it was a dirty play ... I don't think I led with my knee."
Wild coach Mike Yeo felt it was a dirty play by Hall.

"To me, what I saw was a player who didn't even look at the puck," he said. "It looked like he was trying to hurt a guy."

The NHL posted a video as well...