SmartyPants was written by the same coder as the original Markdown and adds the following conversions:
SmartyPants support would be great.
I've never heard of "SmartyPants" but add my vote to support for some form of conversion of typographic symbols.
I agree, SmartyPants support would be an excellent feature to add. It's one of the only things I feel is missing from MarkdownPad.