Manpower is an issue, but we've gotten a lot of requests for Ruby in the future. When and where Ruby support will come is still unknown, but do know that we hear you! :)
I think this would be the right place to bring this up: Is language support backed in or can everyone write a plug-in for his language? Implementing highlighting, completion and repl for all the different languages users could want seems like an enormous task. At the same time this is where Emacs shines: supporting a new language rudimentary is easy to do, adding more advanced support isn't too hard either. Will users be able to define new language modes?