^so far not at all. very little is knonwn about season 2, or even episode 24 and 25 for that matter. though considering that the geass production staff probably don't have a completed outline for something that's months upon months away, its not that surprising.
you can search the spoilers thread for some of the 2ch guy/FO Q&As and magazine posts for everything we know so far, but right now a few things we know about S2 are: