There's a difference between whoring out your franchises and whoring out your characters creating fatigue.
Anyway, to me this looks like an incredible co-op, specifically 2 player game. I think that's the only way I'd want to approach it/buy it, in order to get a feeling of something new from a Mario game. Haven't played a co-op Mario before, so that can be the fake next gen feature/development for the series for me ;p