What's with all the hate for on-rails shooters? The Wii is the perfect console for them as you already have the gun straight out of the box.
But I agree, an on-rails shooter is not the best way to "test" the market. In fact, I don't think theirs is much interest in a Dead Space game on the Wii either considering how poorly the original did on the HD consoles. How about an RTS on Wii? Or a Western RPG? Set Westwood and Bioware to do some ports or something.