If you are running Windows Vista and an NVIDIA 8800 GTS or GTX graphics card you can catch a glimpse of DirectX 10 sweetness via the NVIDIA Cascades demo that uses DirectX 10 runtime.

The demo has lots of rocks in pillar formations along with dragonflies that zip about the screen. Waterfalls are placed at random points and you can use controls in the demo to put waterfalls wherever you want them.
Everything you see on screen in the Cascades demo is generated on the GPU of the 8800 card including the physics that keep the dragonflies from crashing into the rocks and allow the water to run and splash realistically. I think the demo looks really great and it only makes me want for Crysis that much worse! If you have Vista and an 8800 GTX or GTS hop on over to Nzone and download the demo, it’s worth it.