It's not just a markdown->everything converter, though. My install understands these:
Input formats: native, json, markdown, markdown+lhs, rst, rst+lhs, textile, html, latex, latex+lhs
Output formats: native, json, html, html5, html+lhs, html5+lhs, s5, slidy, dzslides, docbook, opendocument, latex, latex+lhs, beamer, beamer+lhs, context, texinfo, man, markdown, markdown+lhs, plain, rst, rst+lhs, mediawiki, textile, rtf, org, asciidoc, odt, docx, epub
Also, it needs to be mentioned that Pandoc supports its own set of (IMO) sensible extensions / defaults to Gruber markdown [1].
[1] http://johnmacfarlane.net/pandoc/README.html#pandocs-markdow...
From the link, scroll down to 'Pandoc’s Markdown' about a third of the way down the page for all the details. http://johnmacfarlane.net/pandoc/README.html