depends on if the audience (and furture generations) want to hear that content. there are a lot of "younger" people who go to those metallica, ac/dc, rolling stones concerts, but when you got 20 year old hip hop fans who already give the

face to dudes like nas, jigga, etc. it's hard to imagine that there would be enough interest to keep these guys touring - i personally don't ever need to see jay (seen him 4 times and will see him this summer) live again in my life, couldn't imagine 20 years from now wanting to go to his concert.
and with the current crop of rappers? no, dudes are replaceable right now, most can't sustain true interest for more than 3 years, let alone 20+. and the content now? who wants to hear songs about Molly, strippers, Bugatti's, etc. at 45? most people either passed that phase or if they're still stuck in it, they're broke or in jail.
anyway, jigga, kanye, and snoop & dre (together), and nas, (drake still too young in the game to tell) are the only cats i could see pulling big numbers if they toured 10-15 years from now