downloaded games should be fine but psp vita cant play umd's for some stupid reason.
Q: Is PS Vita compatible with other PlayStation platform games like PS3, PS2, or PSP? Do you have any plan to support other PlayStation platforms in the future?
A: Users can play supported digital PSP titles and supported minis. In regard to PSone classics titles, we will announce further details when they are ready. PlayStation does not have plans to make PS Vita compatible with PS3 or PS2 titles at this point.
this is was taken from this site- http://www.ubergizmo.com/2012/02/playstation-vita-...