I don't think anyone knew quite what to expect in the quarterfinal match between Federer and Nadal. If you look back over the last couple years there have been two hard courts wins by Fed at the World Tour Finals (complete with a bagel) and Indian Wells, but the most recent matches have been pretty much blow-outs by Nadal (one of those thanks to a back injury that Roger was struggling with). Obviously Roger's form hasn't been great in the last few months, so what should people expect when playing someone who has been in scintillating form? Personally I was getting annoyed before the match, however, reading that almost no one was giving Federer any chance at all to win.
Though he didn't win the match in the end, the great Roger Federer proved to everyone that he is far from done. The tennis he showed, especially in the first set, was the Roger of old. He came out looking confident, aggressive, showing every shot in the book, and with that steely glint in his eye that showed that he wanted this one. And he really was so close to the win. It's amazing how a couple points at the wrong time can completely change a match, which is what happened at 4-5 in the second set when Roger had a bit of a hiccup. He really needed to win it in straight sets, as I think he got a bit discouraged after losing that set and let down a bit.
I am disappointed he couldn't pull it off, but I think he really did find a way to "Get his swoosh on" once again. He is now looking ahead to the US Open with excitement, knowing he has a good chance to go far if he can continue to play as he did in this match. As for Rafa, he is once again into another final, likely another title, unless big John Isner can continue his great form he has been in and win his first Masters 1000 title.