v6.pm now has rule declarations. It still needs some additional work to process parameters, etc. Then v6 will be able to compile it's own grammar, and maybe it will be entirely rewritten in P6 (except for the runtime modules).
Unfortunately, the build is currently broken in windows and osx - at least for unexperienced users, it seems. I'm planning to add eval() around the required binary modules, so that at least a subset of the language can work without XS compilation.