Federer is now certain to be ahead of Sampras for the number of weeks in the top-2 : he's certain to be in the top-2 until after the Canada open at least, which means at least 382 weeks.
Sampras stopped at 376 weeks.
Lendl can be considered quite around the same number although it's not easy to estimate as the rankings were not updated weekly in that time : at most 403 I had estimated in the past.
Nadal is already at 343 weeks
Of course, if Fed wins Wimbledon, he will overtake Sampras for the number of weeks at number 1 and
be a number 1 at 31 years old, which seldom happened ... and
win one more slam
Now with 32 slam semifinals he holds this record alone, not together with Connors.