I think they're keeping Tarzan around for his vote, and that they've promised him the F4 spot in return for his vote. They probably think there's no way he'll pull out an immunity win at F4, when he needs it. Hope they're right.
I think Christina will be the next to go, after maybe Sabrina. As long as Tarzan is under control, Christina can't cause any damage.
I was glad to see Kim change her vote from Sabrina to Kat tonight, however that happened. Kat was a bigger threat to win immunity than Sabrina, and they can get Sabrina out next week. And, the others feel like they got what they wanted, and Kim's wishes didn't dominate. All good for Kim.