That's already more than everything at last year's TGS. Oh, snap! No, I didn't!
Okay, so that's not true, but really, this is quite a lot of games just by three publishers/developers, perhaps in response to the generally poor international response to last year's TGS. (Then again, what were those people complaining about? You were in Japan! I was not!)
Anyway, according to Andriasang and various other websites, the TGS 2011 lineup for Sony, Capcom, and Sega are as follows:
Sony (PlayStation Vita)
BlazBlue Continuum Shift Extend
Dynasty Warriors Next
Asphalt Injection
New Little King Story
Mahjong Fight Club
Shinobido 2
Power Smash 4
Uncharted: Golden Abyss
Gravity Daze
Hot Shots Golf Next
Shin Kamaitachi no Yoru
Disgaea 3 Return
Ridge Racer
Sony (PSP)
Frontier Gate
Final Fantasy Type-0
Yakuza: Black Panther 2
Hatsune Muku Project Diva Extend
Oreshika
Sega [Source]
Binary Domain (PS3/360)
Rhythm Thief & The Emperor's Treasure (3DS)
Hatsune Miku Project Diva Extend (PSP)
Power Smash 4 (PSV)
Shinobi 3D (3DS)
Phantasy Star Online 2 (PC)
7th Dragon 2020 (PSP)
Anarchy Reigns (PS3/360)
Sonic Generations (PS3/360/3DS)
Yakuza: Black Panther 2 (PSP)
Capcom [Source]
Sengoku Basara 3 Utage (playable, stage events)
Asura's Wrath (playable, stage events)
Dragon's Dogma (playable, stage events)
Resident Evil Revelations (playable, stage events)
Street Fighter x Tekken (playable, stage events)
Monster Hunter Diary G (playable in Family Corner, stage events)