How good is Djokovic?

I gave the 2007 US Open a complete miss. Mostly due to the fact that the winner was a foregone conclusion. There is hardly any surprise in men's grand-slams these days. One positive thing out of this years final grand slam was the performance of Novan Djokovic. He has beaten Federer once in the final of a tournament, so he looks capable of causing an upset. I think he competed well in the final of US Open, and had he held his nerve well, could have easily given Federer a run for his money. I am sincerely hoping that atleast next year we don't have the sort of one-way traffic we have been seeing in the past 3 years. Hope Djokovic & Nadal help.