No chance in hell.
Probably the old man has only a couple of good years in him. But even then he will not win any slams. Anyone remember WTF 2010? I heard the same comments then than now and look what happened after.
Some time in the near future, people will wonder whether or not Djokovic and/or Nadal will eve win slams again or regaining their respective rankings; the lesson learned is that players such as these can never be counted out, no matter what historical trends predict and historical trends certainly did predict that Federer was highly unlikely to regain the #1 ranking.
From a historic perspective, this is really unprecedented territory for Federer in one respect.
--He regained the #1 for the second time after having lost it for at least 11 months each time. The first time he regained #1, it took him 11 months. The second time, it took him 2 years and 1 month.
Agassi, whose entire career is the most asymetrical of any great (or otherwise) tennis player's first regained the #1 in 1999 after 3 years and 5 months. He then regained it again after have lost it for 2 years and 8 months. It's highly unlikely anyone will ever do this again.
Connors regained the #1 after having lost if for 2 years and 9 months. While it was a great achievement, it was aided by the sudden departure of Borg from the game.
Sampras regained the #1 after having lost it for exactly one year.
What makes Federer's return to #1 rather remarkable is that he is playing in an era with two other dominant players in their or near their primes in Nadal and Djokovic who, the past two years, have had phenomenal years, i.e., Nadal in 2010 and Djokovic in 2011.