PS Vita will cross platform play with the PS3
Sony has detailed several ways in which the PS Vita can share content and play games online with its bigger home console brother.
Content will be shared between both PS3 and PS Vita versions of games like ModNation Racers allowing players to share tracks no matter what platform they are playing on.
New titles such as multiplayer action RPG Ruin which will be available on both platforms can use cloud saves on PSN to carry on play from PS3 to PS Vita and vice versa.
This is just the tip of the iceberg though with titles like LittleBigPlanet confirmed for the PS Vita some time after launch bringing even more new features.