This needs to be screamed from the hill tops!

To be honest, this is the kind of thing that would be great to highlight immediately on https://github.com/rust-lang/cargo or http://doc.crates.io/guide.html.

I go to those pages and I am given 0 information on how the thing actually works.

Which I guess is normal since it does not create any dependency cycle. A new version might as well be thought as a completely different package (of perhaps similar functionality).