It's very interesting to see what would happen to Fedal next year. To see what was left in their tank. I always believe their fate in tennis were intertwined together, though they are 5 years apart.
I think Federer would win 1 more slam in the next 2 years. As long as he can qualify to QF and SF regularly, he would continue playing and anything can happen from there. I think he can do this as the field before QF is still wide open for him.
Nadal's presence in slams would affect him in tricky way. He has good chance on all surfaces, but he couldn't just face what's thrown in front of him anymore. I think Federer is truly disappointed losing against Berd, because he comes here as the favorite and No. 1 player, so he wants to win a slam with that status, NOT as an "opportunist". But sadly, I'm afraid he has to be more like an "opportunist" if he wants to win a slam. I hope he can win just 1 more slam as No. 1 and the favorite, but it's more unlikely than being an opportunist, I guess.
Even if he'd managed to do the impossible and win here some people would still have called him an opportunist due to Rafa's absence...