I hope Nintendo doesn't eliminate Mature titles from their line-up. Madworld was fun to play, and GTA on DS wasn't bad, but the idea of being fed shovelware for the lifespan of the system makes me green in the face. I purchased a Nintendo WII knowing it wouldn't have the same level of mature titles, but at the same time, I wasn't expecting to see a endless selection of party games with little replay value either. I concur with the sentiment about the WII being a casual gamer's paradise; there's plenty of simple games in the Wii's library to keep those people entertained.
Will mature titles vanish from the Wii entirely? It may happen but only time will tell. I remember reading online somewhere that casual gamers were outraged by the release of Madworld, stating that it tarnished the Wii’s innocent image. Umm, yeah.