That's right...18. Adriasang has the details here

This is as well as 3 unannounced PS3 titles and 1 unannounced PSP title.

The Sony booth is split into three zones: PlayStation Vita Zone, PlayStation 3 Zone and PSP Zone. The games listed here are all playable. It's likely that there will be other games shown in video-only form (so don't start freaking out about The Last Guardian not being in the list).

In the PlayStation Vita Zone, you'll find:

BlazBlue Continuum Shift Extend (Arc System Works)
Dynasty Warriors Next (Tecmo Koei)
Asphalt Injection (Konami)
New Little King Story (Konami)
Mahjong Fight Club (Konami)
Shinobido 2 (Acquire)
Power Smash 4 (Sega)
Uncharted (Sony)
Gravity Daze (Sony)
Hot Shots Golf Next (Sony)
Shin Kamaitachi no Yoru (Chunsoft)
Disgaea 3 Return (Nippon Ichi)
Ridge Racer (Namco Bandai)

The booth will also have 18 unannounced Vita games.

In the PlayStation 3 zone:

Battlefield 3 (Electronic Arts)
Dragon's Dogma (Capcom)
Asura's Wrath (Capcom)
Street Fighter x Tekken (Capcom)
Dynasty Warriors 7 Extreme Legends (Tecmo Koei)
Ninja Gaiden 3 (Tecmo Koei)
Winning Eleven 2012 (Konami)
Metal GEar Solid HD Edition (Konami)
Metal Gear Solid Peace Walker HD Edition (Konami)
Final Fantasy XIII-2 (Square Enix)
Binary Domain (Sega)
Uncharted 3 (Sony)
ICO (Sony)
Shadow of the Colossus (Sony)
Ratchet & Clank All 4 One (Sony)
God of War HD Collection (Sony)
Hot Shots Golf PS3 the Best (Sony)
Happy Charlie to Soratobu Carnival (Sony)
Ni no Kuni (Level-5)

The PS3 zone will also have three unannounced titles.

HELL YEAH! :D It's gonna be HUGE for Vita...and more gameplay vids of gravity daze incoming = win

I like this aggressive approach from Sony. Good stuff.

guys ..correct me if I'm wrong BUT aren't these all about playable games? 0_0 doesn't that mean there can be even more new psv games but only in video format!?

I dont think all 18 are playable.

I reckon out of the 18, a good amount of let say 8 games will be playable and the other 10 will simply be in Video format of trailers, which definitely counts as reveals at TGS since regardless of what format the new 18 are going to be announced, they will have a presence at their Vita booth.

Now to me, I also think about up to 5 of them could be exclusive to Japan only.

But regardless, the fact that Sony has 18 unannounced Vita games ready to be revealed at TGS is just pure amazement and obviously the 18 cant all be Sony 1st party games so the majority will be 3rd Party games, which will ve very exciting to see!

18 unannounced Vita games?
3 unannounced PS3 games?
1 unannounced PSP game?

You know what's coming...

18 divided by 3 = 6 + 1 = 7


Final Fantasy VII Remake confirmed!!!!

I'm expecting 12 of them to be smaller PSN games, which is fine by me.

One cannot find fault in this logic.  VII is a go

that's what you call the perfect set-up.  very well done.

Excellent line-up, I have always preferred TGS to E3.