How is this different from any other language where you "just" run `cd path/to/project; (make || rake || pants || cargo)`? This isn't special, and it's not something the go workspace makes possible.
This is different because $GOPATH is a requirement of the language and in _other_ languages, you have to manually clone the repos in the correct root folder which you store all your code into.
Go allows you to do a go get reponame and it'll do the git clone stuff for you.
that is nothing short of amazing as far as code management is concerned. I love it.
