Does anyone think we'll ever see Airplay built in to the entire OS? Not just from iTunes, but being able to push any sound or video output to the Apple TV? I am running the spotify app on my desktop, and right now the only way to stream it to my appleTV/living room speakers is to buy Airfoil. $25 for the app seems like way too much, given the limited use. But it's something that'd be really nice to have built in.