What would be the motivation for wanting to go back to Super if you had AE? I can't say that I ever once wanted to go back to vanilla SF4 once I had Super. Fighting games tend to be like sports games in that when a new version is released most of the community migrates over.
I suppose since this is a fighting game, the Arcade Edition will have a large following. My concern was if the DLC doesn't catch on, players that buy the Arcade Edition disc won't exactly have many people to play against. My thinking is it would be a good idea for those disc players to still be able to play against the well-established Super players already in existence. Like I said, if the DLC catches on, I guess this is a non-issue.
You weren't around for SFII were you?
I guess I was fortunate enough to be young enough to only know of SFII Turbo back in the day.
Vanilla SFII and the other iterations were realized later in life.