At a press conference earlier today, Sony confirmed the Playstation 4, as well as several launch titles.
The company has expanded heavily on the concept of social gaming--most notably, they've added a live stream system in which you can stream your game screen, receive comments from friends, and even let a friend take over the controller remotely temporarily.
The console will have 8gb of RAM and a secondary chip dedicated to downloads. This will allow downloads to continue after the system is put into a low power mode.
The low power mode also allows for games to be continued exactly where you left off. The game will not be quit when entering the low power mode so the session is preserved.
The Dualshock 4 controller now includes a headphone jack and an LCD touchpad, as well as Move capabilities and a "Share" button. The share button will bring up a video recording of the previous 15 minutes played, from which you can clip desired sections or separate individual screenshots for uploading to video sites and social networking sites, respectively.
Basically, lots of improvements. We have no visual on the console yet, but more will be unveiled in the coming months. Discuss rumors and such here.