Well, we know (according to Olivia) that whatever happened with Martha Logan happened four years ago, and we know that Martha stabbed Charles four years ago. It wouldn't surprise me if Martha went in for mental treatment, and it wouldn't surprise me if we never find out exactly what happened.

Olivia's scene with Ethan Kanin was pretty harsh. But Ethan still looks like a baddie from here (and I have no spoilerish foreknowledge, for those who wonder about that). He was gone from the White House during Juma's attack, and he authorized Jack's interrogation of Ryan -- which was completely known by Hodges' staff and, in fact, included in their plans.

Since Hodges also wanted the President dead, we have to presume that he wanted the VP to become President. But we don't have to presume that the VP is in league with Hodges -- although he may be.

And Bill dying was effective in a way that most of the deaths on 24 over the years haven't been. Bill deliberately sacrificed himself to stop Jack from doing it ... thus, my spoilerish reference above (sorry) to Spock's self-sacrifice in Star Trek II.