Not a chance, I'm afraid.
If the Wii and 360 were seen as interchangeable then sure. But they're not. The Wii is simply regarded as far more desirable by general consumers and a cheaper 360 isn't going to change that.
The 360 would sell more, of course, as the lower price point would allow those who want a 360 but can't afford one to 'Jump In' but it wouldn't really touch Wii sales IMHO.
Try to be reasonable... its easier than you think...







