In my opinion there is market for everything, I don't like the wiimote so I don't like wii games (and yes I played Metroid and Mario and Zelda). On the other hand I see more and more games that I'm interested in coming out or in development. So its not about hardcore or casual, is about taste and I'm pretty sure there are a lot of people that like the games I like so I expect those games to keep coming.
Look at the list of "hardcore" games for 2008, over 25 "hardcore" games, that means that you can play 2 new games every month, that is a lot specially if you are a hardcore gamer who finishes everything.
I didn't buy games for 3 months (nothing good) and bought my PS3 and after that my wii, do the same more variety.







