Ya, Ruby on Rails core is now hosted at GitHub, which is uses Git for easy, fast, efficient, distributed version control system and also which looks pretty!!!
GitHub has now officially launched and Rails is right there at the premiere. The Rails repository now lives at rails/rails
And you can check it out with:
git clone git://github.com/rails/rails.git
But you will first need Git installed on your machine. For those on Windows machine, you can get that here: msysgit
Also people should have a look at this excellent post by Tim Pope on how to best use Git with Rails. You can have a look at the full tutorial also.
