I think people are putting too much emphasis on the price of another console affecting Nintendo's sales, honestly I can't imagine too many people saying, "Wow I wish I had a 360, but its too expensive, oh well, I'll settle for a Wii I guess...". Even then I feel the only consumer who would really be affected by a PS3 or 360 price cut would be someone who already wanted one in the first place. I can't imagine too many casual gamers who would be swayed so easily between two such completely different consoles based solely on a price margin of fifty dollars.
Though now that you mention it, this could indeed be a big upset for Christmass time when Parents are the ones buying the consoles for the kids. If a kid has a wish list and a Wii or 360 are listed as interchangeable choices by the Kid, the parent will probably go with what's cheaper or more available which could mean the 360. And a lowered price tag would put the 360 within reach of alot more kids.
