In response to a tweet from @gl3media, I’ve added a quick modification of the MultiMarkdown to HTML service to the Markdown Service Tools project page. It simply renders the selected text to HTML via MultiMarkdown 2 (Perl) and SmartyPants, putting the result on the clipboard and leaving the original text alone.
This is a companion discussion topic for the original entry at https://brettterpstra.com/2011/09/01/new-markdown-service-tool-html-to-clipboard