Have you experimented with single page web application, i.e. where the browser only \'GETs\' one page form the server, the rest being handled by client side javascript code (one
Maybe you should check SproutCore (Apple Used it for MobileMe) or Cappuccino, these are Javascript frameworks to make exactly that, designing desktop-like interfaces that only fetch responses from the server via JSON or XML.
Using either for a blog won't be a good idea, but a well designed desktop-like blog admin area may be a joy to use.