Apple created its Cocoa development environment out of libraries of code called frameworks. These frameworks exist on every Mac OS X computer. You can find them in /System/Library. There are two kinds of frameworks available: public and private. Recently, super-hacker "Pumpkin" has been looking into the DeviceLink private framework and suggested I take a peek through its strings.
Sure enough, the framework seems to provide device-to-device wireless Bonjour connection support. The framework address incoming and outgoing sessions, device pairing, file transfer, and authorization. What this means is all the technology to connect iPhones, iPod touches and Macintosh computers (not to mention Apple TVs) together, using simple programming with all the heavy lifting done by Apple.
This is a private framework. Like MobileDevice, the framework that powers a lot of iTune's iPod- and iPhone-data transfer, this indicates that this is not a feature that will soon pop up in a public Software Development Kit for easy access to members of the Apple Developer Connection. And that's a shame because the framework is both exciting and intriguing.
If you'd like to look for yourself, navigate to /System/Library/PrivateFrameworks/DeviceLink.framework and run the Unix strings command on DeviceLink. I found the framework both on a Tiger 10.4.10 system with iTunes 7.5 and on a Leopard 10.5 system with iTunes 7.4 as well as the 1.0.2 iPhone files but not on an original Apple TV. So chances are likely that the framework is already on the system you're using.