Apple released today iTunes 10.1. This introduces AirPlay and iOS 4.2 for the iPad, iPhone, and iPod Touch. (NOTE: iOS 4.2 is not yet out, there is just support for it.)

With iTunes 10.1, you can wirelessly stream videos from iTunes on your computer to Apple TV. This also provides important stability and performance improvements.

I just need iOS 4.2 and then my life is complete!