What should the punishment be for this hit? (VIDEO)

Ryan Carter was the victim of a vicious hit from behind during the second period of yesterday's game against the St. Louis Blues. The Blues Kevin Shattenkirk was ejected from the game after his violent hit left the Wild's Ryan Carter down on the ice for several long moments. It can be seen on the replay that Carter hits the boards almost chin first, resulting in his head and neck being pressed against the boards in a frightening manner. There is almost no doubt that Shattenkirk will face some sort of suspension for this hit, the question on everyone's mind now seems to be surrounding the length of that very suspension. You can decide for yourself, and you can watch the play here courtesy of the NHL. Let us know what you think the punishment should be in the comments below.