PS Vita Emulation

[Zekro]

It's because they have to reverse engineer.Also as you said when an emulator is made they need to know first the types of files that require to make them work.Look at the nintendo 3ds for example:It came out for some while but the games use unknown file sistems like CIA or CIX files,which they don't know how to make them work.The same happens with psvita.Maybe with some years it will have an emu.Look at the ps3 for example.