As a former avid City of Heroes player, I wish that someone would do this for shuttered MMORPGs. There are so many, and unlike single-player games that will at least run on old hardware and/or OSes, shuttered MMORPGs are completely inaccessible by any means. (Well, other than server emulators, for the very, VERY few that are lucky enough to have them.)
A while back, I wrote an email to GoG basically telling them that I wish they'd consider approaching some of the publishers of shuttered MMORPGs and offering to host them, either buying the rights to the games outright or licensing them, and charging $10 or $15 per month for access to everything (or offer cheaper plans for limited access to one or some games). Because the playerbase of many of these games would be a lot smaller than the new flashy hotness MMORPGs, it probably wouldn't take that much in the way of hardware, and if they could negotiate access to the source code, they might even be able to rewrite parts of the game to run more efficiently or even release updates. I got back a response that boiled down to, "Thanks, but we're not going to do that."
I still think it's a market that's ripe, and someone at some point will exploit that and make a killing off of it.
Hmm... Anyone got some negotiating skills that could pair with my technical skills to get this done?