At netlify we’re working on an open-source CMS for static site generators. It’s currently in private beta (just shoot me a mail with your github handle at matt@netlify.com and I’ll get you access) and works well with hugo.
We just launched the updated site for http://www.staticwebtech.com/ build with hugo, and that’s the first public hugo site that use netlify CMS.
The idea is to build an extensible CMS for static content that assumes you’re using a generator or build tool and not working directly with HTML. It has a flexible live preview in the style of the site you’re editing and (just like prose) it will turn edits into git commits.
As some others in this thread, I believe a lot in a decoupled approach to this, where the CMS layer is about editing content, and the build tool is about generating HTML and assets.
We’ll be starting to post and talk much more about this project in the next months and will hopefully be ready to open up the repo to everybody soon (we just want the getting started experience to be a bit more straight forward first)…