I tried running AirPlay from my iPad to my Apple TV. It was clear that VUDU and Apple are not playing nice because I got a message that digital rights management prevented me from using AirPlay with VUDU.
For some strange reason, however, you can port you Ultraviolet movies to Flickster and use AirPlay to watch them through Apple TV. So, while I was able to watch the movies, Flickster to Apple TV puts a large black border around the display space, effectively reducing your TV size by 50%. I could not figure out how to eliminate that border.
In a pinch it works, but it is frustrating that the consumer gets burned because these companies are trying to build barriers to entry.