Playstation 4 or whatever name Sony will use for their next gen console is currently codenamed Orbis, a source has revealed to Kotaku. The source claims that Sony will implement an anti used games measures built into the console and unfortunately will not be backward compatible with PS3 games. Furthermore, he provided Kotaku with some basic specs for the console.  Here's the summary:

- The console is called, or at least carries the working codename, "Orbis".

- The console is scheduled for a Holiday 2013 release.

- Won't be backwards compatible with PS3 games.

- Will lock new games to a PSN account as an anti-used games measure.

- New games can be bought either on Blu-Ray or downloaded.

- Current specs are an AMD x64 CPU and AMD Southern Islands GPU.

Don't take these info as 100% confirmed because nothing has been confirmed by Sony and everything could change over time.