* Nadal too weak / lacks confidence after laying off in second half of 2012
* Federer, 32, will fall
Nadal doesn't need a good runup to the clay season to dominate there. Even if he should be too rusty, that should mainly affect the clay masters tournaments. By RG, he should be match fit again. Barring unforeseen escalation of his injuries.
Federer will be 31 for three of four slams next year. He is old enough, in tennis terms, without people talking his age up further. As for his chances, I think the should be good. Next year he'll have an entirely free hand to play what he wants. It is not far-fetched to see him giving less priority no #1 now that he has got the record, focusing fully on the slams.
I would be very surprised to see both of them titleless in 2013.