So here's my theory that I hope doesn't happen. Later in the semester/year Rusty get's busted for cheating and is about to be expelled when Cappie sweeps in to save the day. Since Cappie is a slacker with no future and Rusty will probably run NASA, Cappie decides to take the fall and save Rusty. Casey is so moved by this act of selflessness that she immediately choses Cappie.
As much as I want Casey/Cappie together I think that would be too cheesey. Also, I was way mad at the idea of Casey cheating on Evan last night. Yes he screwed up. But, she got revenge and forgave him. Therefore, I think it'd be totally wrong to mess around behind his back.
