Who can beat Rafa (aka Rafael Nadal) on clay?

Today, I read that rafael nadal won his 72nd straight match on clay in barcelona. It is mind blogging to see that no one has beaten this champion in his past 72 matches. He is the clear favorite (in my mind) to win the 2007 French Open. At Roland Garros, Roger F. has a date with the 20 year old spaniard. I think the French open finals (for the 2nd year in a row) will be Roger F. vs. Rafael Nadal. Head to head, Rafael has the edge on Roger on the clay surface. Is Rafa the best? On his shoes, "Rafa Vamos" is the cliche which is splattered on the left & right arch of his quick feet. As for the sport of tennis, it is one which I started playing at the age of 9. I have had the fortune to meet players (like Tracy Austin, Ivan Lendl, and Andre Agassi) at various tournaments. Seeing Agassi & Sampras play in 1993 was a highlight in my world of tennis. I never saw one of my favorite players, Boris Becker, at a tournament. But, I did see Andre Agassi play a couple of matches in phoenix. Long live the Vegas Wonderkid!