None of the three companies really have anything big planned for the end of the year. They're going to have to rely on the titles that were released earlier in the year for their systems (GTA4, Wii Fit) and several third parties titles set to release. These includes games such as Guitar Hero 4 and Star Wars: The Force Unleashed.
The PS3 actually has Socom, Motorstorm 2, and Resistance 2 announced as big titles for the end of the year. As for the 360, it seems to be dropping Too Human in August, and after that, it doesn't seem to have much good exclusive announced for the rest of the year.
Looking at the Wii, it too doesn't have much lined up for the holidays in 08, at least not as announced. Each of the companies decided to release their biggest games in a select period. For Microsoft, it was holiday 07, and it helped to make their biggest holiday season yet. For Nintendo, it was early 08, and we're seeing phenomenal sales. For Sony, it seems to be holiday 08. We'll see how that goes.
I think that Wii Fit will be a phenomenon this year that will carry over to the holiday season.
