This is being addressed on other threads, but let's give it a thread of it's own. Speculate away!
I think it's probably Paige, though I'm not sure what that's going to accomplish. Still, both Erin and Rob have some history with Paige, so that might be kind of interesting. Hee hee, I also thought it might be funny to see how the two remaining guys react to her appearance on the show.