It's possible there is a rebellion within the colonials, but cautious, the Zarek as president thing may yet be a misinterpretation. It is certain though, that both Bill and Lee Adama will be in major trouble at some point, though why exactly, is unclear. Roslin's question "are you a Cylon" hints that it may be about that, that they believe Bill (and by extensions Lee, at least for 1/2) is also a Cylon, but this may be a red herring as the question and the execution in progress are not necessarily related.
We have firefights both on the ground and on Galactica, apparently. Since the fleet will likely leave (BSG) Earth pretty soon (Eick said the living conditions would be appalling and the fleet would want to leave soon), the big ground fight may be over "New Earth", as the Patriot Resource is speculating. I expect Cavil and co to show up, there.
Edit: some more interesting things here: http://tv.ign.com/articles/894/894082p1.html
From the way it's described, Roslin's question may indeed be unrelated to the apparent execution. For all we know, the Cylons are going to execute him (or pretend to, or attempt to). Or Zarek does, possibly for some other reason.
Also, D'Anna will have a talk with the hybrid. Next episode likely is her last, so must be from there.