@aaronjensen has posted the ASP.NET MVC source code at http://github.com/machine/msmvc. Fork it, implement your ideas (or suggestions as failing tests), then appeal to the ASP.NET MVC overlords for inclusion.
(I heard @haacked is one of them.)
On the same note, @jschementi pushed up IronRubyMvc a while ago. It’s an extension to ASP.NET MVC to support IronRuby. According to the README, it lets you write your controllers (and presumably other parts of your site) in Ruby.
Welcome to the Hub, MVCers!