If the 360 price cut helps push sales in the Americas, Halo 3 has a chance to sell better. Still, I don't think it will. This holiday season, the 360 will have lots of new titles (Gears 2, Fable 2, Saint's Row 2, Left 4 Dead, Tomb Raider, etc.). These games will all sell well and provide a lot of competition for Halo 3.
Exclusively, the Wii doesn't have that many games lined up for the rest of the year. Most of the Wii's big hits this holiday season will be either multiplatform third party games (Star Wars: The Force Unleashed, Guitar Hero, various sports games) or first party games from 2007 or early 2008 (Wii Fit, Mario Kart, Galaxy, Brawl, Wii Play). Consumers looking for hit Nintendo games will be catching up on older titles they missed, and Super Mario Galaxy will be getting plenty of shelf space.
Not only that, but we're looking at what could be record breaking Wii sales numbers due to alleviated supply and increased demand due to the release of several hit titles. While 360 hardware sales will definitely be strong, Wii sales will be even stronger. I would give the battle to Super Mario Galaxy, although Halo 3 will win in the long end due to its long term selling capacity. Either way, it will be close.
