Not sure how many of you have looked at SPD recently or have designers who design pages but they had made some changes which made the
. However the story has improved there is a feature in SPS2013 called Design Manager which allows you to convert HTML files into Page Layouts and Master Page. The engineer that I discussed this with also mentioned something called Design Packages which maybe a possible answer as well.
Essentially you can use editor of choice to edit the HTML page using snippets, and then on a publishing site use the Designer Manager feature to convert that HTML page into page layout and Master page.