Uncharted 3 multiplayer, will be free to play, at least if you believe the recent segment removed from the official U.S. PlayStation blog. They have revealed this kind of information: "Uncharted 3: Drake's Deception Multiplayer (Free to Play)."
As part of this announcement was soon removed, I was not able to throw around and take a little more information. But this confirms Naughty Dogs statement, from the end of last year, and he said:
"As for the third Uncharted.. we will have some very exciting information concerning multiplayer component at the beginning of the next year. "
With all that in mind it seems that it is only a matter of time when the multiplayer component of Uncharted 3 becomes free to download and play via PSN.