To avoid falling to No. 5 Federer will not only have to do well at Wimby - he'll have to win it. Otherwise, only early tournament collapses from Ferrer and Nadal will prevent another milestone stage in his decline.
Go now Roger so that people can remember the good times - not the mediocrity you're putting out now.
Yes it's going to be very hard for Federer to stay in the top 4 after Wimbledon. Ferrer's not defending any points in Canada, Cincinatti or Shanghai compared to Federer defending 1360 points (plus 450 Olympics points that will come off) so it'll be difficult for Federer to stay ahead of him.
Obviously Federer isn't what he was, but personally I'd probably keep playing as long as I could. Look at someone like Hewitt - he used to be the best player in the world, but hasn't been anywhere near that for years. Yet he was still there giving it 100% at Queen's. I think that's far more admirable than just quitting as soon as you lose a step. Most players would love to be number 5 and still reaching the latter stages of slams.
I agree - if Federer was concerned about his ranking then he'd have played in Miami and Monte Carlo. Last year was probably his last big rankings push as he wanted the most weeks at number 1 record. I think he'll keep on playing until he starts losing early in slams to players he'd usually beat easily. He obviously still really enjoys playing tennis so there's no reason to stop just yet.