Yes, TGS is open to the public (last two days anyhow) so it's a good way for nintendo to promote the WII U. I think the confrence (13th) will be addressing "western" concerns. Namely I'm expecting more "port" annoucements to be made (Tomb Raider, Bioshock, Medal of Honor, Modern Warfare, ect).
At the TGS I'm expected to see more Japanese style games like JRPGs, I'm expecting some sort of Sqaure/Enix support, and some loving from Capcom (RE6).