Officially announced games:

None

They do state there will be new game announcements

Guesses based on sponsors:

The PC Gaming Show is sponsored by Bohemia Interactive, CyGames, Nexon, TripWire, and Xbox.

Bohemia Interactive: Arma 3? DayZ?

CyGames: Shadowverse, though we don't know if they're bringing anything else as well.

Nexon: LawBreakers?

TripWire: Probably a mix of Killing Floor, Red Orchestra, and/or Rising Storm

Xbox: This will presumably just be some of their games from the Microsoft conference, so see that list

Additional notes:

They could definitely do a better job making this sound exciting. Let me know if I missed anything about this.