Would there be any real interest in this? My thought about set-up would be something like...I could create the gallery, then initial categories - ie, Ourselves, Games We're Playing, Our Pets, or whatever the heck people wanted (I could hold a poll on categories to be included, maybe) - people could upload to those categories and be able to edit/moderate their uploads and the comments under their own pictures if they want etc.
Then as time went on, if users wanted a new upload category (because of a big new game release, say), they could request it and I'd add it; so it'd be an evolving community thing. The only problem is in order to make it "obsidian members only" I'd probably have to have people PM me from here on the forums so I could register them manually. Haven't thought that through yet.
But obviously I don't want to do the work to make it/maintain it if no one would be interested...