If it's not HL2: EP3 then judging by the "zombie" reference on the crowbar, maybe it's Left4Dead 3 or some other zombie game...
You know, I hope I'm wrong about the HL3 thing really
As much as it would be great, I don't see it happening.
Wrong type of crowbar, wrong color to boot.
The zombies thing, I think, is just a play on the crowbar reference in general.
More importantly, that's why they say "zombies, or..." and half the Nvidia logo after that. That same half logo was also displayed on the 590 box/crate used for the press reveal. Not sure if they'd used that approach at any other time (quite possible), but usually they use the full logo for anything/everything, as opposed to that fancy splash of only a part of the logo.
HL3 should be sometime in the next year or two, I'd reckon.