This is probably my favorite episode to date. It really brought home how much the show helps you care for the characters (anybody else cringe when Tigh started drinking, again?) and lightened the dark mood with some well needed humor.
I personally don't think that either Adama is a Cylon, but I'd put my money on Apollo over the commander any day of the week.
That being said, I think Ellen is almost *assuredly* a cylon - but it could be that the writers were just playing up the suspicion.
Only time will tell.
All I know is that I can't wait to see more! Next friday can't come soon enough!