Agreed. The branching model used by the git project itself is quite effective. Introducing an additional tool isn't always needed.

http://git.kernel.org/?p=git/git.git;a=blob;f=Documentation/...

If there existed a git-next tool to document that workflow then it might be more widely known, I guess. There probably is no tool because it's all just normal git stuff.

The document mentions:

  - The tip of 'master' is meant to be more stable than any
    tagged releases, and the users are encouraged to follow it.