The Sunday play didn't take that long, so Andy's physically got lots in reserve.
Federer's play has been improving through the tournament (as always), but as with the Nadal match, I think if Andy smells blood then he'll win it ... and I think Federer's gonna make enough mistakes to lose one of the first two sets.
So Andy in 4 or 5. Damn, gotta choose. 5 then.