Dustin Howett, developer of Safari Download Manager, has ported the recently discovered LowTide app, which is basically the Apple TV application, to the iPod Touch 4G.
Clearly not everything is going to work. AppleTV was never meant to be used on our iDevices, so things like touch response and resolution will be out-of-whack, but I'm sure after some tweaking we may possibly see something more usable here. As interesting as this sounds, its no easy task to maintain and modifying some of the data to get the app to work can be rather risky.
This port is NOT available for download as of yet, and the requirements to do so can be painful, even Dustin says it's not entirely a good idea. Chances are, you'll end up needing to restore your device after playing around with it. Nontheless, you just might see AppleTV coming to your iDevice in the near future. Who knows...
Fun fact: The AppleTV2,1 FrontRow app is NOT signed. It lacks any trace of LC_CODE_SIGNATURE, and gets Killed immediately.