Re: Will Federer become number 1 again?
No. In my opinion to do so he would have had to have won this year's USO or at least made the finals to have a chance. The Toronto final, Cincy win and USO final/win would have provided an ideal start to his 12 month rankings if he were looking to recapture #1 after Wimbledon next year.
As it is, the points swing to Nadal in the big tournaments has become very considerable and will only increase in the near future with Rafa defending fewer points than Roger in the WTF and the Australian Open. What's more, I would not bet against Nadal having a stellar clay season next year either. So unless Federer wins 2 titles out of the WTF/AO/Wimby as well as going very deep in Indian Wells, Miami and the clay court tournaments, realistically I cannot see him taking back #1 in the next year. And if not in 2011, then when?
Of course by his own phenomenal standards, this year has been a bit of a disappointment. But even still I believe he will end the year as #2. Looking ahead, he'll still be contending near the top of the 2-4 rank bracket (which may be no mean feat for a 30 year old, especially if Del Potro can play at his US09 level again).
I think there's something quite powerful about Federer being one week short of Sampras in the total weeks at #1. If only he had converted from any of the following scenarios: being 2 points away from beating Del Potro at the USO, 2 points away beating Davydenko at the WTF, 1 point away beating Baghdatis and Berdych at Indian Wells and Miami, not having to withdraw from Dubai due to a lung infection, not deciding to play Monte Carlo...then the situation could have been so different.
Just goes to show that the margins in tennis can be very thin at times.