Regarding the discussion on how long the band might carry on for, I think that at this point they'd go for ten more years, or five more albums.
They can release an album every two years and tour behind it, concluding things in 2035 for the band's 50th anniversary. Jordan will be 77, James will be 71, which is not that close to how old some of the Deep Purple and The Rolling stones guys are, and yet they're still out there.
Of course, adjustments will have to be made regarding some performances, but still, it could be done.