Another random idea: Add an option to encapsulate images in svg tags for full-screen scaling (or at least scaling to display size). I'm thinking something like the svg cover option in calibre, but usable for any image in the book, maybe as a right-click option in the book browser. It is tedious to do manually because you need the image dimensions to ascertain a proper aspect ratio (afaik, I'd *love* to hear an alternate solution).
This might be a little late in the game for 0.6, but I'm throwing it out there anyway