Sony demonstrated at Tokyo Game Show that PS Vita will be capable of remote play with PS3 Games.

The games shown were Killzone 3, played fully on the Vita (like you can currenly remotely play PS1 Games on the PSP), with the back touch panel used to replace the DualShock 3 buttons that the Vita doesn't have, and LittleBigPlanet 2, for which the vita actually worked as a Wii U-like controller, addding touchscreeen functionality to the PS3 game played on a normal TV.

You can see a few pictures and a video of the demonstration after the cut.