There's a WYSIWIG editor called htmlarea at http://www.interactivetools.com/iforum/Open_Source_C3/
One of the mods was to replace the <P> tags with <br>. Javascript IIRC. One of the problems was that is screwed up lists as each list item ends in a hard return.
I always thought something could be done with css by using a different paragraph class for rte paragraphs. You could specify a different bottom-margin for those paragraphs. Might not show within the rte, but could show on the post page at the least.
Something else for the "One-of-these-days" list