That said, if you ignore the doubts and arguments about the sanity of its dependency resolution algorithm, I think vgo's introduction of modules is its real contribution.
Go packages have been problematic since the start since their design, naively, conflates a bunch of concepts that most developers keep separate: File location, file structure and source repository. That is, when you do 'import "github.com/foo/bar"', there's a whole bunch of conventions at play that dictate where it can be fetched from and where it should be in the file system. Aside from the fact that the $GOPATH convention is maddeningly annoying to many developers, the design has several issues, such as that an entire git repository has to be fetched in order to use a nested package, or that a package can have multiple import paths. But getting rid of $GOPATH is in itself a huge deal.
I'm personally less concerned with the new MVS algorithm (though I personally prefer the more traditional lock file approach such as that used by dep, Cargo, Bundler, NPM, etc.), as long as I can get modules. While getting modules retrofitted into depwithout all the other stuff in the proposal would be lovely, I don't know if the module design is too dependent (heh) on the rest of vgo's versioning thesis to be separated out.