During E3, Sony promised that during the summer an update would be made so that PSOne Classics could be played on the PlayStation Vita. Sony is making on that promise by announcing that in firmware update 1.8 the much desired feature will be added.
Unfortunately no exact details were given outside of the firmware number. We will have to wait a bit longer for an exact release date and what titles will be supported initially.
The highlight is that soon enough gamers will be able to play every Final Fantasy before Final Fantasy X on their PlayStation Vita pending the release of Final Fantasy III for the PSP in digital form.