Apple has announced the iCloud app Photo Stream - it brings the cloud to photos. When a photo is taken with one of your devices, it will be sent to the cloud and then to all other devices, including the Apple TV - automatically.
Photo Stream may be an individual iCloud app, but it is tied into the already existing Photos app on iOS devices. There will now be a new album called "Photo Stream". On a Mac, you will find it in iPhoto, and on a PC, it will be the Pictures folder.
Apple will store the most recent 1000 images in the cloud for 30 days. Move them into a different album on your Mac or PC to save them permanently.