I'm wondering the same thing- I am trying to do an IAD-PRG-MUC-IAD trip next September and not sure what to do- book as soon as the window opens in Nov or wait until January. I am thinking it's a crap shoot. I'm platinum, so one of my options is to book in November, then in January, see what happens, as I can always cancel at no charge and re-book using the new redemption levels. We'll see, but knowing delta.dumb and their greed, I suspect it will be 1.) a crappy rollout with many things broken the first month; 2.) worse rates than before to further devalue our miles.
Lisl