The latest PS3 rumor is that Sony will release free online play but thats just for the person who bought the game new.
You first register yourself on Sony network
-you buy the game and play it online
-you get bored of the game and you try to sell it away
your friend buys it from you, puts it in his console and want to play it online
-Message arrives on screen:
dear customer this game is already registered on GAMERX profile. IF you want to play this game online plays pay X euro thank you.
This is just a rumor for now, but it is still an interesting one.