Hey guys, I wanted to contribute something here that might be helpful.
Before I crossed the darkside and bought my iPhone, i was into HTC Wizard modding, and after reading this request, i remembered that there was a group of developers who created themes for a homescreen app called "weatherpanel".
And two of them come to mind one is PhatPhingerIII which is located here:
[THEME] WeatherPanel Freaks: PhatPhinger - a "stylus-free" QVGA theme - PPCGeeks
This fellow was able to create a very nice, clean theme that he based on the HTC Diamond. I used it on my wizard and it was pretty nice to look at.
This next one is a very updated one that I also used (I used a theme that wasn't animated), that is much more Diamond.
[Updated 3 Sept] Diamond WeatherPanel Theme v5.4 - More Animations and VGA Layouts - xda-developers
The reason that i am sharing this, is cause these fellows have already done the leg work to get the animations going, and my thought was that perhaps whoever is developing this for the iPhone might be able to get into contact with the person who did it for WinMobile and use their images to help out for this project.
I also thought that i should add that the image files used to create these are included in the downloads so there is no extraction involved. At least there wasn't when I was playing around with them.
And if memory serves the images are in .png format, but it's been a while so i don't exactly remember.
I would love to see this developed for iPhone too!