The editor used to edit posts at medium.com is a real slick, and I find it interesting and intuitive. Davi Ferreira have made an open source clone of it, so it could easily be used in other places.

@cweagans have done great work to get the Medium editor in it's own module, but I would rather myself have it inside the WYSIWYG API. so I took some parts of his work and did a patch, so if somebody else finds it interesting to get this editor to work with WYSIWYG API, please try it out, test, review, throw stuff at it...

As a first step I just added the text editing part, with further plans on try it to get it to work with Asset for images, videos etc.