Final Fantasy XI is still alive and kicking and getting regular content updates across all three platforms it runs on -- the PC, PlayStation 2, and Xbox 360. The next update in development will add something very interesting that seems to be aimed squarely at the higher-level players of the game who may be getting bored.
A new Level Sync feature will allow higher-level players to "power down" and adventure with lower-level ones and earn rewards similar to how the lower-level players would earn them. It scales them down to the lower-level player so they can access lower-level areas with them and will also scale their equipment down. This way high-level players don't have to scrounge around for lower-level equipment to go adventuring with their lower-level pals.
This sounds like an inspired game feature and shows that the FFXI team is committed to retaining as many higher-level players as possible by letting them enjoy earlier areas they might have enjoyed again with other lower-level friends. This should also boost mentoring as well since there's incentives for letting higher-level players replay these areas.
For my own adventures in FFXI, check out this thread. For the details on the content update see the Newsletter Issue 26.