Well considering the fact that Epic games said that GoW is over and that they will probably not do a GoW4, and that Sony seem to want to milk the Uncharted franchise as much as they can (4 games in 5years + the fact that Sony rely on golden abyss for being Vita's system seller pretty much confirm us that Sony will do everything they can to have a Uncharted 4 for a PS4 launch). Because of that I say that it will eventualy, but only because the UC franchise will have wayyy more games on the market.

But if we only consider the games that are out right now, the first 3 UCs vs the first 3 GoWs, then UC has no chance in hell even if you add golden abyss to the list.

EDIT: Sorry I just noticed that the question was for 2012 only. So my first paragraph is irrelevant. 

The Gears franchise is at 18.28 million lifetime, Uncharted is at 17.07.

Take away 0.88 million to 16.19 if you wanna keep this 360 vs PS3 based.

Glad to see Gears held its own with the holiday 2012 Uncharted 1-3 bundles (yes all 3 were bundled).

The Gears Of War franchise was at 19 million back November, also these are sold through numbers:

Even better. Gears wins.