I think it would be great to allow fog of war to be effected by auras on tokens (to represent sight range and/or light sources). So, for example, the GM can set the map to be entirely fogged out, but the Cleric with the Light spell on his shield would reveal a circular area around him automatically. This would then probably require occlusion effects to work correctly. Essentially, the GM would need to be able to draw lines and shapes that represent boundaries that light can't pass through. That way, the Cleric can't use Light to see through walls and doors, for example. It's really hard to simulate fighting in darkness in real-life games, but the nature of this interface would probably make it work well if implemented.
