Though Uncharted 3 isn't officially on shelves until Tuesday, some have found it through independent retailers where the game already is in stock. Naturally, you get a game before its street date, you go through the online menu just to see what's available, even though Uncharted 3's online access doesn't begin until November 1.
In so doing, some have found premium skins for the game's characters, listed with a preview image. Multiplayer functionality doesn't begin until November 1. DualShockers suggests that it means the game is drawing its previews from the disc, which means when you buy these premium costumes all you're doing is unlocking content already on the disc.
As this image from Reddit shows, players can preview selections like Wetsuit Drake, Cameraman Jeff or Nepal Chloe. That said, Uncharted 3 does have a quasi-Online Pass-ish "Fortune Hunters Club", which offers some online stuff to those who buy at retail, but must be paid for if you get the game used. Maybe these skins are part of that. It still looks a little cheesy.
Uncharted 3 May Have Day One DLC Already on the Disc [DualShockers]