Making markdown opt-in rather than default
I've seen some cases where markdown has badly messed up the formatting of the discussion context panel, particularly when people cut and paste text in from other places.
I think markdown is awesomely useful when people know how to use it, but that's a small minority of our users. Would be super keen to switch it to opt-in. I'm suggesting this as a short-term quick fix - ideally it would be awesome to have a basic formatting GUI like Gmail, so ability to format text isn't limited to the tech-literate.