So, all the TGS stream schedules are up and can be found on Gematsu :
http://gematsu.com/2017/09/tokyo-game-show-2017-live-stream-schedule
Here's what I think could be interesting to look forward to (in termes of announcements/details on games we don't know much about) :
Atlus : Saturday, September 23, "Shin Megami Tensei Series 25th Anniversary Goods and Event Information", they'll probably talk about the concert and upcoming events, maybe dropping some tidbits about SMTV
Bandai Namco : September 23, 13:15 to 14:00 "13:15 to 14:00 Sword Art Online Game Live at TGS 2017", it's unspecified which SAO game they're talking about but since they're getting the seiyuu on stage they'll probably talk at least a bit about Fatal Bullet, the new one.
Capcom : September 23, 14:50 to 15:35 + 15:35 to 15:50 "Ace Attorney Series Special Courtroom 2017" We may get a tease/glimpse of what's next in the serie, or more mobile port announcements.
16:00 to 16:45 "Dragons Dogma Series 5th Anniversary Special Stage" They're probably just going to talk about Online and the Dark Arisen port but eh, you never know.
September 24, 14:20 to 15:05 + 15:05 to 15:15 "Mega Mans 30th Anniversary is Almost Here! Stage" They're supposed to release a new mobile game by the end of this fiscal year, so they'll probably reveal it here. Ready for another anniversary that will last five years ?
Dengeki : September 21, 16:30 "Ryu Ga Gotoku Studio New Titles Broadcast", they're suppose to play Kiwami 2 and will deliver new infos on both Hokuto no Ken and Shin Yakuza, so it's a pretty important stream.
DMM Games : September 21, 11:30 "Gal Metal Stage Announcement" the new Switch rhythm game produced by Tak Fuji and that was teased a few days ago in Famitsu.
Koei Tecmo : September 21, 13:00 to 13:45 "Dynasty Warriors 8 Special Stage" We'll finally be fixed on if it's still planned for this fiscal year or not, and new footage to judge the progression. They really need to show the game under a better look this time.
September 22, 15:30 to 16:00 "New Brand Midas Introduction Stage" It's the new mobile game brand that Koei Tecmo opened a few months ago and which we don't know much. They're going to properly introduce it.
September 23, 12:00 to 12:30 "Attack on Titan 2 Special Broadcast" This one is interesting because Koei Tecmo said when they first announced the game that the platforms choice wasn't closed yet and they were looking at the feedback. It could also contain the first footage of the game.
SEGA : September 21, 12:00 to 12:45 "Dx2 Shin Megami Tensei: Liberation Live", introduction to the new mobile SMT game.
13:00 to 14:15 : Yakuza again
September 22, 13:00 to 14:15 : more Yakuza
14:30 to 15:15 "Phantasy Star Online 2", they will likely talk about the recently announced Phantasy Star Online 2 Cloud on Switch
15:30 to 16:15 "Atlus Title Stage (Tentative)" ???
September 23, 10:30 to 11:00 "PopoloCrois: Narcias Tears and the Fairys Flute" it's the recently announced mobile PopoloCrois game, it will be properly introduced here.
And more Yakuza & DX2 Megaten for the rest of the week.
Playstation : most of their streams concerns already announced & well known games.
Square Enix : September 23, 11:35 to 12:20 "Final Fantasy XV Active Time Report at TGS 2017", it's FFXV again !
It's a completely arbitrary list, there may be stuff I omitted.