I’d really prefer not to fork the language; I’d much rather collectively help carry the banner of Markdown forward into the future, with the blessing of John Gruber and in collaboration with other popular sites that use Markdown.
So … who’s with me?
I’ve been thinking about this a bunch. Obviously, we use Markdown quite a bit at Jekyllhub. But, since Gruber hasn’t offered any kind of endorsement, I think it’s highly likely this will end up as a the n+1th format. As one HN commenter pointed out, Jeff makes no mention of MultiMarkDown, which has a test suite and compatibility guide.
Jekyllhub might add support for Rockdown / Markdown v2 / etc… I’ll probably stick close to whatever Github Pages does. As long as it’s a useable, simple format that clearly and cleanly compiles to HTML I think it will be a good fit for us.