DX10 is a lot more than pretty water. It includes better hooks for physics, more realistic smoke effects, much improved shadowing (also covered at the link I posted earlier), and vastly superior particle effects and interaction. I've attached a screenshot of the DX10 particle effects when compared to DX9. The difference is pretty amazing.
DirectX 10 will also bring some pretty interesting improvements to the sound arena once the major sound vendors get used to the OpenAL API. Perhaps one of my biggest grips with Vista is the elimination of most aspects of DirectSound, leaving lots of old (and new) games sounding like crap with stereo sound. Creative Labs seems to be making some strides in repairing that damage with ALchemy, but the verdict is still out on whether or not ALchemy is going to do the trick.
For what its worth, I'm not just a DX10 fanboy. The last couple revisions of DirectX haven't really been all that breathtaking, but DX10 really has the potential to take gaming to the next level. Not only will games look better than ever, but the improvements in sound and physics will make games far more immersive. Imagine Half-Life 2's physics kicked up a notch! I had more fun with the gravity gun than I did with the rest of the game combined, and I can't wait to see more innovation on that front.
I don't get to play games nearly as often as I would like to, but I really appreciate beautiful games. If I'm playing a game that is truly engrossing and worthwhile, I want to play it with all of the settings cranked so I can view it the same way the creators did. A person stricken with cataracts can't appreciate a Degas painting the same way a person with 20/20 vision can because they can't see it the same way the artist does.
Briney, what's your take on this?
On an off-topic note, just last night I started playing
Dreamfall: The Longest Journey, and I can honestly say that it's one of the most beautiful and engaging games I've played since Riven. Although its beauty is tied more to the artistic direction taken by the producers than the API its running on, I can only imagine what this game would look like if it was redone in DX10. If you guys are looking for something completely off the path, this game is truly amazing.
-b0b
(...was all over the place in this post.)