If nintendo were to make a new ip, what genre should it be?

[Andrespetmonkey]

Action RPG or FPS. Doesn't have to be the usual gritty and grey, but something targeted specifically towards a mature audience.

I guess there is X, but that looks more JRPG-ish which isn't what I'm looking for. I'd like a more western style plox, and I would hope from a western dev.