Following on from Erica’s Sadun’s discovery of a way to enable AirPlay Video streaming in third-party apps, a developer named Zone-MR created a hack which enables this feature in all applications including Apple’s Safari.

This is big because it means Apple could easily (and will likely) enable it in future versions of the iOS.

The hack itsself can be downloaded from this Cydia repository:
(and it should be available in other repositories soon)