Holy's original function should also have purged Jenova from the world. Granted, since Holy *failed* in the (more important) task of annihilating Meteor, it's entirely reasonable to believe Jenova survived. What "she'd" probably have to do is lay low, gather herself back together, wait a couple centuries, and try again. Or, if she still has the kind of emotions and ego that one could presume of a sentient, she'd get *REALLY PISSED* and go off on a psychotic final assault before getting herself back to full power.

The Advent Children and Dirge of Cerebus "sequals" to FF7 should have some more info about what happens with Jenova. As well as everyone else. Unfortunately, we have to wait a little while for any definates on that. I don't speak nor read Japanese...