prosfilaes
Adventurer
But without D&D around, many of the surviving FLGS will close up, which in turn will leave the mid-tier game producers with no great outlet for their products. Online sales are fine, once people know they want your stuff, but you need something to drum up that initial enthusiasm.
Pandemonium, in Boston, had one or two solid bookcases of D&D, last time I looked, but they also had four bookcases of other RPG stuff, a floor of sci-fi and fantasy paperbacks, and a strong collection of miniatures and board games and M:tG. Little Shop of Magic, in Vegas, has a bookcase of D&D, a bookcase of Pathfinder, and one of other RPGs, along with a wall of miniatures, a large collection of board games, and M:tG. Even the death of D&D and all those players just disappearing still is unlikely to kill either of those FLGS. They're game stores, not RPG stores.