Adobe has launched a version of Lightroom for the Apple TV which lets your view your synced photos on your TV:
With this Lightroom for Apple TV release, you’ll be able to share your photos one by one in a slideshow, with the ability to stop and zoom in to see all the detail within your photo. Quickly navigate through all your photos to find that exact memory you’re looking for.
I have to admit, when I first saw this in my RSS reader I had to check that it wasn't the 1st of April. It's a good idea though, so I look forward to trying it out.