While Sony has no IP with the same strong sense of identity that Nintendo and Microsoft has with the exception of GT, it DOES have the biggest internal studio lineup of all 3 console manufacturers; a launch menu that carries a GT within the first year as well as a plethora of titles from the like of Naughty Dog, Santa Monica and Guerrilla Game will more than keep them competitive.
Think of it this way. If Sony launches the PS4 with a God of War IP, Uncharted IP, Killzone IP. LBP IP etc, would you really scoff at all those brand name simply because individually, they don't have the same power as a Mario or a Halo?
Barring GT, no IP in Sony's arsenal is strong enough to carry a console by itself the way Halo or Mario can, but if Sony plays there card right and consistently support their console with a combination of reasonably popular brand name as well as new IP, then I foresee no issue with the launch of the PS4.
