A lot of people I know, most of them grown men who play lots of violent games, consider this game to be a bit too much. I've been watching these videos, and I agree it's a little excessive - however, by the same token, it looks like all this gore is attached to some pretty entertaining, and quite deep gameplay. I know i'm looking forward to it.
I fear that with Nintendo's install base being primarily composed of -very- casual gamers, this sort of thing just might not sell that well. Even being the Wii fanboy that I am, I recognize this. This could be catastrophic for "mature" games like this, or maybe more adult-oriented games in general on Wii, because third-party developers and publishers could interpret this as an indication NOT to produce "hardcore" or "adult" games on the console. OTOH, everyone and their brother has a PS2, including people who like this sort of thing.
Admittedly the Wii's attach rate is terrible, so I think this game might do more harm than good to the Wii's software library, which is already seeing a huge trend of childish, or "family-oriented" games as opposed to a more diverse library. read