Hillary is done after this term.
She's already been on record saying that she wasn't going to do more than one term as SecState, although I've also heard 1--she wasn't moving to NY state to run for the Senate, and 2--was going to focus on the Senate and not run for President in 2008, among many other whoppers.
Whether Obama wins or loses, she's gone. SecState is an incredibly stressful job and IIRC, the last person to hold that job for more than one term was George Shultz, and Dean Rusk before that. Couple that with again, whether Obama wins or loses, she's got to get her resources together for a possible presidential run in 2016 (although I don't think she'll go far at all and the events of the last month have pretty much sealed her fate.)