Still no news on the date that the epilogue will actually air, but this article from the Miami Herald tells us a few more details:
1. The new epilogue contains little dialogue, and is mostly montages and music.
2. Makeup and clothing were enhanced to comport with 1969, and to make Jack and Helen look older.
3. JJ went to Berkeley to bring Meg home.
4. Chris joined the violent wing of the anti-war movement.
5. NBC actually canned the show in December and was ready to shut it down after 13 episiodes, but Prince cut a sponsorship deal with Kraft and Oreo to extend the season to 17 episodes.