Homebrew is giving me warnings about XCode 5.0 being out of date, but the developer site isn't specifying 5.0.1 as Homebrew is asking for and I don't have an available update in the App Store.
I had some trouble reloading an existing vagrant box and virtualbox, seems to have resolved itself after using each providers uninstall tool bundled with the latest versions of Vagrant and Vbox and installing fresh versions after.
I don't usually use sudo to install virtualenv, you can use the method here and it will work: http://stackoverflow.com/questions/4324558/
I had some trouble reloading an existing vagrant box and virtualbox, seems to have resolved itself after using each providers uninstall tool bundled with the latest versions of Vagrant and Vbox and installing fresh versions after.