Remark is "a simple, in-browser, markdown-driven slideshow tool." There is already a project somewhat similar to Dillinger which supports it, called Markdowner, but I like Dillinger and would like to see if it could support Remark as well.
Interesting slideshow using markdown. First, awesome. Second, your FR is pretty broad-based. Just seeing it be supported is so wide open I have no idea how to scope this in terms of level of effort to do this.
My recommendation is to fork Dillinger and see about how you would incorporate Remark into it and submit a pull request so I can see what it looks like.
Separate project altogether. Not a dilinger bug or feature request.