I've been thinking about leveraging existing open source interfaces for static site generation, creating something between a full cached (Varnish, etc) interface to a dynamic site and generating each page on the fly. So rather than have Wordpress or Drupal or some such thing generate the full site the new post is dumped into the existing static site generator and a site generation pass is triggered.
I'd prefer to retain some dynamic site features like commenting, discussion, and form submission. While there are very successful companies that outsource these features I prefer to have the option to take ownership and control of my content. So I'm envisioning the only dynamic part of the site besides the admin interface is an API to enable these (and more) features. Depending on design and the type of interaction these could trigger a page or site rebuild or update a Javascript framework on the page to reflect the new comment, the successful form posting that updates a calendar, etc.