Federer: Will he do a change-up on Rafa?

After watching the great tennis match last night between Wawrinka and Nadal that Wawrinka played with such skill and no fear, I was brought back to thinking what I have thought many times since having watched that seven hours of hell when Federer lost to Nadal after returning service with his backhanded righthand service return hit. Had to be tiring. I cannot play tennis; played in college but that is way to late to start. I've always been a swimmer. While I was in Japan, I had a swimming coach/trainer who had been on the USA Olympic Swimming team. He was watching me one day doing the American crawl/Australian crawl, breathing on my right side as my right arm was pulling back making the trough. He stopped me and said, "Your head is coming up about an inch. Everytime. Not good. You are almost stopping in the water. Take your breath on the left side as your right hand is going down into the stroke and your left hand/arm is pulling back." I made that one adjustment. My head never comes up again, ever when doing that stroke and I never take a breath on the right side. Never. Now my head stays level in the water, makes the slightest turn, hardly any turn at all really, and all because of that one modification. What has this to do with the greatest tennis master in the world? I don't know but watching Wawrinka got me to thinking about that one tiny change that I made and I was wondering if there is one tiny change or modification that Federer will made when playing Nadal that will throw Nadal off of his game. Don't get me wrong. I love Nadal to win and beat everyone but Federer and del Potro but last night Wawrinka did something I hadn't seen happen to Nadal before. Nadal was off his game and Wawrinka was not afraid not one tiny bit of that lefty's serve, not one tiny bit. Will Federer serve left-handed to Nadal? I hear Nadal is a natural righty. What will Federer do to take that one extra step to reach down into his gut and bring up the full majesty of his power? Not just the technical accuracy but the beauty and majesty, the warrior power he hides from us... I don't mean emotions, I mean the warrior power, the mental skill, the near-oriental finese. Basically, I just like to watch Roger Federer kick tennis ass! Well, he wins over Roddick and I couldn't find the match on TV any place...