The AirPlay Mirroring app would basically allow the user to stream whatever is on the display of their Mac computer to an Apple TV, which in turn could be hooked up to a projector, television or an external monitor. This will be useful especially in meetings where information has to be shared with multiple viewers, or maybe for those who prefer a bigger screen to work with (if they’re using a smaller display like the 11” MacBook Air).
iMessage for those who are unfamiliar, is Apple’s answer to RIM’s BBM. It was featured in iOS 5 and basically allowed iOS 5 users to send text messages between each other for free as long as they have some sort of internet connection. It has been speculated that this feature would make its way onto OS X Lion, since code findings for iMessage support has been discovered in the iChat application.
While AirPlay Mirroring may not apply to the majority, especially those who don’t own Apple TVs, the iMessage application or integration with iChat will definitely be a feature we will want to see in OS X Lion updates in the future.