Sorry for the late reply, I was out most of the day today. Yesterday, whatever.. it's almost 2AM here.. hehe.
Rigid Body Simulation... That one I'm not entirely sure about, since rigid models don't need any sort of simulation, except when they come into contact with other rigid bodies. This may indicate that cars will actually truly ride on the ground now (as opposed to simply putting the car "x" cm above the ground and letting the model do the rest). It could also indicate the damage system.. poly deformation based on how the car impacts other cars or walls or whatever. Those examples, I would think, would fall more under the category of Collision Detection. Or, as mentioned, the "tires through the fender" thing. Rather than letting the model and a few algorithms figure out positions, it may be a lot more physics-based this time (which would mean more realistic body roll, etc).
Normal Mapping - This is like "super bump mapping". It's a very complex effect if you look at HOW it works, and I'm not entirely sure of all the behind-the-scenes stuff myself. But basically, it gives the appearance of high detail on a very low-poly model. But it does it much more effectively than bump maps do. With normal maps, you can also simulate large details, like door handles or manufacturer logos, and they would appear to really be there, they wouldn't just look "textured on". This would work for things like the gaps between body panels and doors, which would actually look like real gaps instead of just shallow grooves like you'd get with a bump map. It could also be used to add texture and depth to the track and the environment.. rocks would look much more like real rocks, with real detail, instead of just textures.
Antistropic Lighting - Man, you guys are asking the tough ones.. lol. Well, let's take a basic example.. if I were to make a CGI compact disc in LightWave, and shine a virtual light on it, it would simply be illuminated, with standard reflections and specular shading (the reflection of the light itself, commonly referred to as a "hot spot", like a glint of sunlight off of something). With an antistropic shader, the light will "stretch" and it will take on that "CD-ish" appearance, where the light reflections seem to radiate from the center of the disc. For cars, it would add that much more realism to the paint. The light will behave as it's supposed to behave, as opposed to a "standard" reflection or specular highlight.
Now, some others that I find interesting:
Reflection - Finally we'll be able to see the other cars reflected in our own cars. And things like spoilers should now be visible in reflections.
Light Mapping - This one, hoo-boy... Think of the Alfred Molina demo. The game samples the surrounding environment (which is lit HDR, rembember, for enhanced realism). Then, based on the environment, it determines where all of the lighting is coming from, what color those lights are, and how bright they are. It then applies this to the model as sort of a luminosity map (or a dedicated, dynamic lighting rig, I'm not sure exactly how they're doing it), simulating radiosity-style lighting effects. As an example... let's say you had a white car. Not only would it pick up white light from the sun, but it would also pick up blue light from the sky, gray light from the track, and even green light from the grass. The result? Hyper-realistic lighting, like we've never seen in video games before.
