I think some of the PT will stand the test of time. The caring for the characters is there in Revenge of the Sith. Everything seems to click and you get a wonderful film. I think the characters of Qui Gon and Darth Maul are interesting enough for people to atleast enjoy TPM enough to watch it occasionally. AOTC, the verdict is still out.

It all depends on what GL does with them. If he brings them back out, SE's them and gets the editing RIGHT in the first two prequels, I think they can be really great films. Insert more of Maul's scenes back in, cut down on Jar Jar and remove the childish reactions of Anakin, and they will stand up without question.