The developer Dustin Howett has managed to port AppleTV software called Lowtide to an iPod Touch and run it under iOS 4.1. You can see it on a demo video below. It's really amazing how compatible these new systems are.
Here are comments from the developer:
This is FrontRow, as shipped with the AppleTV 2 (ARM), running on the iPod touch, 4th Generation. It doesn't respond well to touch input, nor does it like the resolution of the device.