I think people make a mistake and assume that a game has to be exclusive (and/or first party) in order to be a meaningful game for a platform. Regardless of whether the game is available for other consoles, there are many people who would buy a Wii to play games like Starwars: The Force Unleashed; possibly because the gameplay might be better, because they think the Wii is a more interesting product, because the Wii is much more affordable, or because it is just the cool product to own.
On top of this there are several exclusive third party titles which go unnoticed but have potential to be excellent games, and sell well if they're marketed well. Certainly, I wouldn't make a long list of titles and bet that they would all be million sellers but I do think that there are quite a few titles that could be break-out successes and outperform a lot of (over)hyped titles for the HD consoles.
The last thing I can say is the title being released this holiday season which has the best selling previous version is Animal Crossing so I wouldn't ignore it as being a major release.
