For me, Markdown has singlehandedly revolutionized the way I can put together articles for MacStories without wasting hours over HTML and RTF issues.
Totally agree on this. It has changed everything for me too. It's a relief to not have to fiddle with Rich Text Format (RTF), like Microsoft Word, Google Docs (Google Drive) and the likes. Its so much easier to write in Markdown, without lifting my fingers from the keyboard to format text. Just write in Markdown and it gets formatted automatically. After writing in plain text using Markdown, you then can just export it to any format you like, Word, PDF, RTF, HTML or what ever you need. So simple to do blogs, visual documents, manuals and all other kinds of documents.
Personally I don't really understand why there isn't more people that see all the benefits with Markdown? I think they don't understand that the final product gets the same and even better than using Word or Google Docs… And Plain Text is universal and has no compatibility issues.