If you hadn't already heard, the Versus Booster Map Pack for Gears of War 3 will be free to download on Thursday courtesy of Mission: Impossible - Ghost Protocol. It features the maps Bullet Marsh, Clocktower, Azura, Rustlung, and Blood Drive for use in social matchmaking playlists.
I'll spare you the lame quotes. By finishing the campaign on Insane difficulty (in single-player or with friends) and watching the Mission: Impossible trailer before December 25, you'll get a themed weapon skin pack. I know how much you love those silly things.
Already accomplish this feat? You're golden. And even if you're unsuccessful, merely trying enters you in a contest to win separate prizes. The exclusive skins are for the Lancer, Hammerburst, Retro Lancer, Gnasher Shotgun, and Sawed-off Shotgun.