Personally, I suspect that whether we see games at TGS will heavily depend on when Nintendo intends to release the Wii U.
While I think it is unlikely that Nintendo would release the Wii U prior to E3, it is entirely possible that they would release it before E3 or soon after. If this is the case, both third party publishers and Nintendo might be looking to other conferences (Gamescom, TGS, GDC) to premiere their games and gain coverage leading up to the system's launch.
On the other hand, if Nintendo is aiming for Q4 2012 I would doubt we would see much of anything at these conferences because I would expect most to hold off until E3 (or later conferences next year).







