http://uk.wii.ign.com/articles/765/765721p1.html
I've only played a little bit of Killer 7, and I've played only a little bit more of the original Manhunt. Both were pretty darn graphic. Now the creator of Killer 7 is promising his next game on the Wii, "No More Heroes", to be 'as violent, or even more violent than Manhunt 2".
Should be interesting to see how this game turns out. It looks crazy already, from the little bit of it I've seen.