I'm curious to know if there are any animated themes that react to you moving your blackberry around. Pretty sure anything but the Storm is a most likely not but I am just curious to know. Also are there any themes where the wallpaper is animated and moves around. Did a search found nothing.
I don't believe that are any but you could try the 9700 Themes forum. One thing to remember is that animated themes will consume a lot of memory meaning fewer resources for apps.
I don't believe there are reactive ones (like Eclair, I presume?). There are some that can have animations, but not like the Nexus One.
Check the Themes forum for more info...the people that post there are typically very knowledgeable.