It would be great if people were allowed to play any dungeon at any level, at least as far as dungeon roulette is concerned. It's boring playing the same ones over and over again. At least for me as a player who doesn't get into other expansions as quickly by the pace of play. Just because I don't have that much time to play.
Daily roulette is a great thing but it would be nice to play other dungeons. Maybe with some scaling set for rewards so that one can't get the same thing that other players have already unlocked due to playing msq.
+ Would of course leave out pure story instances that would contain bigger spoilers.