If Parvati or Sandra win immunity, it will be interesting. I think that Russell will vote Sandra afterall (even though she would be a smart one - from his viewpoint at the gametime - because she won a million), Parvati and Sandra I think will vote Jerri and Jerri I'm not sure. We could end up with a 2-2 tie no matter who wins immunity save possibly Parvati - as everyone pretty much sees her as a huge threat to the final three.
The only advantage Parvati has as well as Sandra is that she is a previous winner. In the case of immunity between this duo, if Russell has Immunity, I think Jerri will be out. If Jerri wins it'll be either Sandra or Parvati, and probably leaning toward Parvati.
Sandra - if she does by some miracle win immunity, will keep Russell, and the others will be a wild card. I do think she'd be smart to keep Parvati, as she is unliked by a lot of the jury. Jerri is the only one who could win in a landslide at this point IMHO.
Final three will be very interesting.