@ the prof - I get your point, and I understand your fear of a fading away of core titles. Nintendo will always have Metroid and Zelda iterations in their core/serious libraries, plus with the new IP, Day of Disaster. Also Nintendo has part/most control on Eternal Darkness. They do still have something to offer core gamers, even if they are trying to court the casuals with "non-games" like Wii Fit. Other studios will pick up the slack and bring core games to the Wii, as they go where there is a gap in the library. The issue is people who are core gamers, own a Wii, but don't go out and get the core games because they'd rather play games on other consoles/PC.
Also, you need to remember the origins of games. Prior to the NES, there were not a lot of games that actually had endings. In the days of Atari 2600, most games never ended, just got faster and more difficult until it was impossible to beat them. The 2600 was the first casual system, even more casual than the Wii (1 button and a joystick), and it was the father of all of the consoles that would come thereafter. So maybe Nintendo isn't doing anything original with courting casuals, but just going full circle back to the market they abandoned over 20 years ago.