Inter-App Audio - With Inter-App Audio, apps are able to share audio streams with other apps, an API that will make it even easier to use Apple's iDevices to create music.

Apple recently added Audiobus support to GarageBand on iOS, and it seems to have picked up a lot of industry support. Now we have a home-grown API for letting music creation apps communicate. I look with some interest to seeing how this one plays out.

UPDATE:

Thanks to Jamie Bullock over at uiux.io for alerting me to the Audiobus team's response on their blog. They sound positive, but there must be a question mark hanging over the future of the technology.