Two possible new titles found in website source code: "Thirteen Mecha-Soldier Defense Zone" (PS4, PS Vita) and "Lexus" (PS4, PS3).
http://www.siliconera.com/2015/09/10/sega-might-have-a-new-vanillaware-title-to-announce-at-tokyo-game-show/I've been thinking about the possibility of a Shenmue HD announcement recently, and while I'm still keeping my fingers crossed for SEGA at TGS, I think it's more likely that Sony is going to do it at Paris Games Week or some other event, just like they did with Yakuza 5 and Shenmue III. They are the ones we have to thank for all of this after all, they're taking care of the whole Shenmue resurrection business.
Edit: By the way, there's already a list of games SEGA is going go show at TGS, it's just not the complete one yet:
Phantasy Star Online 2 [Vita, PC]
7th Dragon III Code: VFD [3DS]
The World End Eclipse [Vita, PC, iOS, Android]
BLADE ARCUS from Shining EX [PS4, PS3]
Miracle Girls Festival [Vita]
LEGO Jurassic World [3DS, Wii U, PS4, PS3]
Criminal Girls 2 [Vita]
Yuusha Shisu. [Vita]
Steins;Gate 0 [PS4, PS3, Vita]
Chain Chronicle [iOS, Android]
Chain Chronicle V [Vita]
Monster Gear [iOS, Android]
Chaos Dragon [iOS, Android]
Puyopuyo!! Quest [iOS, Android]
Hortensia SAGA [iOS, Android]
Sakatsuku Shoot [iOS, Android]
Ange Vierge [iOS, Android]
Kingdom Conquest II [iOS, Android]
Sonic Runners [iOS, Android]
Sen-no-kaizoku [iOS, Android]
Xuccess Heaven [iOS, Android]
Odin Sphere Leifthrasir [PS4, PS3, Vita]
http://personacentral.com/odin-sphere-leifthrasir-confirmed-for-tgs-2015-current-sega-tgs-lineup/