I’ve noticed that support for emulators are often requested on OpenELEC’s forums, here’s a couple of threads for example:
http://openelec.tv/forum/13-miscellaneous/33340-openelec-and-rom-emulators http://openelec.tv/forum/128-addons/38614-openelec-game-console-emulators
Now, I don’t claim to know what it takes to make a project like this successful, but it does seem like the few attempts to make this a possibility end up becoming abandoned as people lose interest in keeping the various emulator builds updated for OpenELEC’s system. This is where I think RetroArch would be the perfect candidate since one of your end goals are to support as many systems as possible. I think if you guys could look into maintaining a build that targets the OpenELEC system then it would help to provide a solid foundation for others looking to create an official add-on that would install RetroArch across it’s various system builds.
Again, I’m not sure how much of an effort this would require on your part, but I feel that OpenELEC would be a great platform to target as it’s fast becoming a popular solution for building dedicated entertainment systems.