Looks pretty nice in that vid...
I'm curious as to why the reflections only update at 15 fps, though. PGR updated reflections at 30 fps while the game ran at 60...but if you're running at 30 fps you should not halve the reflection update rate.
I would also like to see some other devs use texture layers as they did in MotoGP1 and 2. As you increased your speed, lower resolution textures would take the place of the ultra high-res ones in order to convey a faster sense of speed. You can't focus on the fine details at such high speeds and it was a great way to demonstrate this. Forza isn't exactly a fast game, though, so it isn't a big deal...but I still want to see other racers try it.