"Thanks to our friends at Guerilla Games, Insomniac Games and Sucker Punch Productions, we’ve been able to a pull off something unique within the UNCHARTED 2 competitive multiplayer modes – our first DLC release is the UNCHARTED 2: Among Thieves PlayStation Heroes Skin Pack. The PlayStation Heroes Skin Pack contains seven new skins featuring some key personalities from other major PlayStation first-party titles – Sev and a Helghast soldier from Killzone 2, Nathan Hale and a Chimera from Resistance 2, and Cole (both good and evil variants!) and Zeke from inFAMOUS. The UNCHARTED 2: Among Thieves PlayStation Heroes Skin Pack will be available for purchase globally on the PlayStation Store on January 28, 2010, for $4.99 in the US. If you’re outside of the U.S., check your local Store or announcement for region specific pricing."
No word on if these skins will come with any unique abilities, though in all likelihood they won't. However, I'd love to play through the single player using a Chimera skin. The cinema sequences would be hilarious.
There is also a demo dropping for the few who haven't played the game, but really, such a person doesn't exist at this point. And if they do, why are they your friends?