You MUST be joking or weren't into tennis back in 2006.
Federer's forehand was absolutely abysmal last night. I am positive Federer never missed easy forehands the way he did last night back in his prime. In fact, Federer was vary that everyone avoided his forehand so whenever he did get a chance to hit a forehand, he made it count. His forehand is still good, but movement effects that shot quite a bit and Federer just seems weak when he forced out wide to the foreahnd.
I've always considered this a weakness of Federer. I remember Patrick McEnroe making a comment during the 2009 Aussie Final about Federer hitting his forehand well when moving to his right (and noted that he had often struggled with that). Just look at some of the comments in this thread from 2005.
Federer does not really have weakness and maybe the most balanced defense and offensive game in history.
But if you have to pick one, his 1 handed backhand and forehand on the run when stretched
wide (these two are things that Safin exploited).
And maybe if he had stronger net game, he could have easier time with Nadal...
I assume that is why he hired Tony Roche....
http://tt.tennis-warehouse.com/index.php?threads/what-is-the-weakness-of-federer.28194/
http://tt.tennis-warehouse.com/index.php?threads/rogers-weakness-in-his-game.63866/
I don't think moving him about to his right is anything new. He's been vulnerable to that play for a long time.