Wait for an Apple TV fix.

AppleInsider:

Several discussion threads on Apple’s support forums related to issues with HD rentals not loading and HDMI connectivity problems have reached hundreds of posts in length as increasing numbers of Apple TV owners report having trouble with the device.

Here are some problems being reported:

  • HD rental wait times can get really long. Some Apple TV users were able to solve this problem upgrading to faster Internet connections but some who have fast connections are still experiencing this problem. There might have been traffic jams on the Internet connecting to Apple’s servers and then streaming to Apple TV boxes. Apple might not be ready for millions of people to be renting HD movies using Apple TV.
  • Some Philips and Sony TVs show inverted colors connected to the Apple TV via HDMI. I am not sure what is going on here but Apple TV and some TVs aren’t communicating properly through the HDMI connection. One thing you should know: it isn’t the cable. Don’t waste money on an expensive HDMI cable. A digital cable is a digital cable and a cheap one will work just as well as an expensive one.

If you haven’t bought an Apple TV yet my recommendation would be to wait for an Apple TV firmware update that fixes these problems.