Pandoc not only creates lean, crisp html from markdown text, it makes clean, crisp ebooks in EPUB format.
This article got me started thinking about ebook automation
http://puppetlabs.com/blog/automated-ebook-generation-convert-markdown-epub-mobi-pandoc-kindlegen
But wait, there’s more!
It is possible to automate even more using the Make and makefile tools. It is possible to make all the formats or just some of them on command.
http://timotheepoisot.fr/2013/05/18/make-pandoc/
http://george.sudarkoff.com/markdown-pandoc-workflow/
Going to read up on that next.