Hi dale1953,
I was not aware of the Wimbledon bigger balls factor...interesting.
All I can say though is that Nadal, Djokovic and Nalbandian are all possible competition for Federer at Wimbledon as well as the other surfaces (not clay as much except Nadal of course). It took Roger longer than other greats to start winning majors, and when he got it going, some including myself, feel he lacked the depth of competitors that other greats had. Now though with Nadal and Djokovic entering their primes, it's harder to claim that. So, 2008 will be a crucial year for Fed.