I think the real battle is between the 360 and the PS3. The Wii is indisputable success and neither the 360 nor the PS3 are likely to ever catch it in sales. However, the Wii market overlaps alot of the same market as the 360 and PS3 so I think it's prefectly fair to pair off the two HD consoles and not consider the Wii for the moment.
Between only the 360 and the PS3, I'm going to say that the PS3 will continue to be a bit sluggish in game sales. The biggest surprise of '07 was the slow sales of PS3 exclusives when compared to multiplatform titles. The 360 versions of multiplatform titles also just blew the PS3 out of the water. This solidified the position of the 360 as the lead console for most multiplatform games. The PS3 is being sustained by much of it's sales outside the US, but the US market for it is still lackluster and that will continue to hold the system back for the rest of it's life.
Thank god for the disable signatures option.
