Right, the rvm install instructions and RVM itself both remind the user to do so, and I think unless you specifically pass an option to rvm, it will append the rvm source line to your dotfiles, if I'm not mistaken.

Do you think it would be acceptable to simply point the user to the docs for [RVM](http://rvm.io/rvm/install) like I did in the README, and say "install RVM", rather than duplicating the instructions here? (we could also include the link to [rbenv](https://github.com/sstephenson/rbenv); developers are free to install ruby 2.0 however they like.)