I was talking to a friend tonight, and we're both hoping this is true. The thought of the NC resistance being comprised of 4 Cylons is kinda mindboggling. But it would fit if the Final 5 are philosophically opposed to the actions of the others.
I suspected Anders was going to be one after he was signed to a contract for S4. Tyrol? Due to him finding the Temple and his reluctance to destroy it. Tori? Never suspected her, but I wouldn't have been surprised. Tigh? That's the only one that doesn't fit. He fought in the war. Could the Final Five have started to infilitrate that early in the pre-series?
Interesting spoilers even if it they turn out to be false.
All of this depends on the nature of who and how the "skin jobs" came to be. We really don't know any of that yet.
I had Tigh pegged as a Cylon after D'Anna applogised to the hood figure.