I think Pete should, because he won't have any more motivation to do it anymore (that he said he had one grand slam left, so there you go). But Andre won't. He's still doing so well, so why not keep going.
I still firmly beleive that Pete is waiting till the day that Andre retires, so that he can retire the day after - steal all the limelight, and have th glory of getting into the hall of fame a year before Agassi
No way will they retire at the end of this year. Sampras himself said he'd be back next year, to keep deluding himself I suppose (although he might up and win the US Open . . . not that I care anymore, it's been such a sucky tournament since Monday ) and Agassi is riding too high, I think.