That's now, what, five times in five years without a win over five sets?
2 Roland-Garros, 2 Australian open (slow hardcourt, first match in 5 sets and Fed was the most dominant during first 4 sets, last one in the only cold day of the fortnight, slowest possible conditions), 1 Wimbledon (9-7 in final set).
Nadal is 8-4 against Fed since that FO 2008 final (included)
Based on these stats, it would be hard to argue that Federer hasn't got a FAR bigger chance of winning a major NOW if Nadal is not around, or is carrying an injury (or whatever it is this time).
bigger chance yes, far bigger, absolutely no. He can lose to many other players and so can Nadal (notably to Djokovic, and Nadal was near to losing in Wimbledon early rounds several times before the Rosol-match, like Federer against Falla or Benneteau)