I've done a few thigns;
1) I've put vehicles back in. I took them out while I was refactoring my scene, but its good to be able to speed around and imagine what the finished product will be like.
2) I've added point lights to my render pipeline. These use the traditional deferred render method of drawing spheres for each light with depth testing disabled and back face culling enabled.
3) I've added a crude particle system; I plan to make this component based, with a list of emitters and a list of forces. The current one shown here is just a crude single vector for the force.
4) I've added a scene node which comprises both a light and a particle system, for making things like fire, explosions, and sparks which have both a light (to approximate the colour of the particle system) and the system itself. The image shown above is created using this system; it makes the light flicker from reddish orange to whitish orange, and it has to be seen to be appreciated. I should get fraps or something.