I don't think rubyonrails.org is too bad, but it could still do with some updates. For example, it doesn't recommend railsinstaller.org to the Windows folks, even though that's the quickest, one-shot way to install the entire Rails and Ruby stack on Windows.

And I don't think linking to a tarball with the Ruby source should be the first link to getting Ruby.. there are tutorials they could link to that would be more useful to newcomers.

Nonetheless, rubyonrails.org is better updated than ruby-lang.org in any case, and provides a better model to follow IMHO.