Is there any consensus on an improved/extended Markdown?
Between MultiMarkdown, Github Flavored Markdown, Stack Exchange's additions, this new "elegant" markdown and others there seems to be bit of fragmentation in this idea of a simple markup.
No, there isn't really a consensus. FWIW, this is not a "new elegant Markdown", this is a 100% standards compilant Markdown library, with optional support for some extensions that we found useful. The syntax for these extensions comes, basically, from the Markdown mailing list and PHP-Markdown Extra.