Has any franchised moved to multiplatform and not sold significantly more on its original platform on the first entry?
MGS is still going to be seen as a PlayStation franchise, least for ground zeros. Couple that with a brand new console it will move units. As many as MGS4? No of course not.
Infamous is easily going to out sell the previous 2 entries and will be a system seller.
Its the tech showcase for the PS4. Unlike Killzone, it is in a genre that has a low skill barrier of entry, it plays to sony first party strengths (story telling, facial animation, performance capture) and by using a new protagonist, it manages to stay as fresh as a new ip, while remaining familiar to fans of the series.
Whether it sells better than titanfall overall Is probably out of the question, but the idea that the game wont cause a significant bump in system sales is wishful and naive thinking. The xbox one is sure to take march, but Im dubious about it significantly taking march.