My Reaction to the rumor being false:
Mains: Prishe, Bartz, Sephiroth, Onion Jerk, Kain Highwind
Subs: Warrior of Light, Gabranth, Lightning, Squall, Jecht, Tifa
I find that term meaningless, though -- because much as the Vita is technically PSP 2, there are a lot of differences between them to the point that I actually consider them to have little or no relation (except for partial backwards compatibility with PSP titles).
Much to other people's dislike -- I would actually be very happy if Versus XIII also finds its way to the PSP.
But eventually I will be getting a Vita anyway, because of certain titles that have been announced for it.