I've also implemented a couple of special effects: menu fades and desaturation fades. Desaturation is used when pausing the game and when the menu comes up. Menu fades are more complicated then you might think, because the menu is composed of overlapping widgets so you have to composite them offscreen before blending them onto the backbuffer.
Here is a shot of a rendering with black outlines. I'm planning to use standard shading with outlines as sort of a compromise between realism and toon-shading.
Here's a WIP shot of the UI. It uses skins, defined using dictionary and image resources, loaded together as a theme. Themes can be swapped at run time, allowing for different themes depending on which character you're controlling.