Sooner or later, Fed will have an injury. A knee, a shoulder, a rolled ankle, or most likely his back.
When that happens, he will be finished. He has done this long enough that he will not want to do the hard work to regain his old form, even if this were possible. Not to claw his way back to making the semis of slams before being bounced.
If I had all those GS titles and all that money and two kids, I would want to go out on top with grace and dignity. Not desperately consulting Safina's back specialist to fix me up so I could lose in the semis one more year.
-- Random Error Generator, Version 4.0
-- Master Moonballer