I must admit, I did think Resistance 2 would have better sales than it did, so if Uncharted 2 suffers the same fate, then... again, I would be surprised.
But Since L4D just came out last year, (meaning gamers are full of L4D, and only the most hardcore will buy a second that really should have been DLC anyways) I think Uncharted 2 will sell more.
Plus Uncharted is basically Sony's Best new exclusive this generation, and Sony has alot of them.
Plus I can see Sony bundling this game later on down the road.