I would imagine any program running simulations, rendering environments, analyzing metadata, and similar tasks would be able to use it.

It would be useful for academic researchers, gamers, hobbyists, fediverse instances. Basically whatever capabilities they have now, they would be able to increase their computing power for dirt cheap.

Someone could make a fediverse MMO. That could be cool, especially when indie devs start doing what zuck never could with VR.