On GTA4: This game will single handedly destroy the PS3. It will be massive on the 360, with extra content and a cheaper console. 360 already has a positive buzz, with Halo 3, BioShock and Gears of war, all games that appeal to a huge part of the PS2 owners that will make the step to current-gen with GTA4. Sony doesn't have anything to offer once the game arrives (maybe MGS4 will be there) that comes close to 360's amazing line-up.
If MS is smart they lower the price before GTA4. Sony cannot match that because of angry shareholders.
LBP: I dont think it will be massive, it will be more like a cult game. Something for the fans, not casuals.
Smash Bros: Be prepared for Wii sell outs
Wii fit: see previous
Mario Kart: Same, same
FF: Not in 2008
Wii 3rd parties: gradually more quality games will come, but no 360 like level.
360 will keep outselling PS3 ww next year.