Who will compete with Federer?

Another Grandslam. Another win for Federer. He has reached 10 slam wins no time. The world of tennis fans have begun to fall into 2 categories: one who admire Federer for his incredible talent and other who crave and yearn for some competitor to come up and provide a semblance of fight. Needless to say, I am in the second category. Tennis was one of my favorite sports during the Sampras-Agassi glory days, but ever since Sampras got disinterested in tennnis and Agassi's powers started to wane, tennis has no longer been the same it was. Federer has arrived and conquered everything he saw, but deep within himself he must have a feeling that he has never been tested by anyone consistently. Nadal competes with him in clay ( small relief ) but it is just a matter of time before Federer wins French Open too. And it is hard not to notice the kind of support every tom, dick and harry gets on court when they play against Federer. You can see that the crowd is also craving for an upset.
The pity is Federer can do nothing about it. He can only beat what is in front of him. It is not his fault that his competitors are worthless. These are the bunch of guys who Agassi was consistently beating even in his last year on the ATP tour.
While I appreciate the enormous talents of Federer, his breathtaking strokeplay and his exemplary off field behaviour, I do feel he has a lot to prove to be adjudged the best ever.
And for anyone who thinks Federer's domination of Roddick was the best ever exhibition of a genius, I am sure you have not seen the Sampras-Agassi final at Wimbledon 8 years back. Here is an article that exactly echoes my thoughts on this issue. Sampras at his peak against Agassi at his peak, and what a game of breathtaking beauty!
Federer can still claim to be the best ever if the following blank gets filled.
Bjorn Borg- John McEnroe
Pete Sampras - Andre Agassi
Roger Federer - ??????????

P.S: This article has no intention of insulting Federer. As I said, it is not his fault that the competition is bad. This article is for those who just jump at concluding that Federer is the best ever, without understanding what the best ever means!