Apple has quietly updated its second- and third-generation Apple TV set top boxes today to make it work with iOS 6 features…
AirPlay – Send audio content from Apple TV to AirPlay-enabled speakers and devices (including AirPort Express and other Apple TVs). Also includes the ability to require an onscreen code to use AirPlay with your Apple TV.
So now, instead of having an AirPort Express base station + speakers in each room for iTunes, plus planning in parallel to get a stereo receiver and a set of speakers for my living room to use with the Apple TV, I can use the investment in AirPlay devices to have kickass surround sound when I watch television shows in my living room.
I have no idea what took Apple so long to do this, or why they waited until now, but HELL YES.