What Carmine said.
Anyways, people need to realize, which most do not, is that the ESRB ratings are very comparable to movie ratings. Giving something an "AO" rating would indeed be censoring it by pressure, and that rating is reserved for very extreme things. In fact, I believe BMX XXX received only an "M," right?
The issue won't be the ratings, it'll be popular reception of the game, which, I think won't be too bad, considering no one is upset about boxing being rated "E," even though it could be used to train kids to beat each other up. Seriously, you practice beating up caricatures of people you know. It doesn't get too much more realistic than that, and no one cared.