I think that Sony will announce the following (or at least i hope they do):
PS3:
New model announced - possible price-cut
Uncharted 4 announced or teased
GT6 let slip - possibly for PS4 (kept very tight lipped on specifics)
inFamous 3 announced
PSV:
Memory Card price-cut and permanent bundle of the 4GB card
New IP announced
Gravity Rush 2 (wishful thinking) announced
COD Vita information
Bioshock Vita information (wishful thinking)
PSOne system software update dated
Assassin's Creed III: Liberation demo
Unexpected big announcement (wishful thiking)