According to GamesRadar (who struck out on their last PS3-rumor at bat), Sony might be looking to prevent the sale of pre-owned games by using a software licensing system similar to the one employed in the PC software space.
The rumor goes something like this: instead of purchasing the actual game, you purchase a nontransferable license to play the game, and the physical media is just a distribution method (think Microsoft Windows). While Sony does own some patents that might be used to this end, the issue is far more complicated than the technology and motivation behind it. Sure, Sony and most publishers would love to cut off the parasitic used-games industry, but would they do it at the expense of angering both retailers and consumers? Considering the dubious origin of the rumor -- "retail sources" -- and GamesRadar's past inaccuracy, it's far too early to get upset over this one.
Next-Gen offers their (similarly skeptical) take on the rumor, getting responses from an expert in retail law and two publishing sources who, though admittedly in favor of such a plan, concede that the story is unlikely.
[Thanks, SickNic and Kerina]