I idly wonder sometimes if there's enough of a user base to justify restructuring end game to take on more level progression, another tier of dungeons and skirmishes, and basically being able to find more gameplay ways to improve your character as an alternative to The Grind.
I wonder what it would take, game-development-wise, to let someone progress to say, level 99 (after a bit of a 'plateau' at 70, since so much existing content revolves around it).
I'm honestly not up on how the real-world-pencil-and-paper D&D handles this... I haven't played much of 4.0 and up... so I don't know if there's just no good starting point from actual d20/D&D to build off of.