I enjoy this game a lot, but that’s never gonna happen. DC is owned by a MAJOR corporation, and the kind of cash that would be involved to buy the rights for an RPG would probably be a half a million at least. All this goes for Marvel as well.
Why do you ask though? If you want a game set in the DC universe, just do it. There are a lot of sites and threads that have write-ups for DC’s characters and DC has an official website that will give you all the backround information you could ever use on your PC’s, NPC’s and locations. And any particular questions you have can get answered in places like this.
As long as you’re not making and selling a game for profit all this come under the “Fair Use” exemption of copyright law.