Okay, I know it's bad to work on the front-end before the backend. But I've went ahead and done some of the basic stylistic stuff, just for fun. This is far from done, but shows how easily themeable the thing is(Each theme took less than 5 minutes). Also it is slow due to google pages, it will be blindingly fast when run locally as it is meant to.
Here are 3 themes I whipped up(Using public domain images of course):
The only image differences are the top image and the status bars on the download page. Obviously this will mostly be dynamically generated(Save for the css and images) by the local web server gui monstrosity.