At Retronyms we have been preparing for iOS7 ever since we first heard about it. Updates for our apps are on the way. Not only are we working on an update to AudioCopy but we are also supporting new features like InterApp audio in Tabletop and other apps.
Some developers are reporting issues with the new audio system. After developing with the new iOS7 tools we haven't found any issues. InterApp audio is working well for us and is pretty exciting for the future of iOS.
In order to help things along we thought we would release the core audio code we are using for some of our apps on iOS 7. This code can be used to make an Inter-App host or an Inter-App node and is compatible with AudioBus too! We like the code at atastypixel.com and we have expanded on it in order to add Inter-App support.
Apple has videos online and some example code. However, the example code doesn't show how to use RemoteIO with Inter-App audio. We put together a sample project that shows how to make a Inter-App Audio node. It even includes a handy to use class you can expand on for your projects!
audioController = [[AudioIO alloc] initWithAudioComponentDescription:desc
name:@"Sine"];
audioController.delegate = self;
[audioController startIO:YES];
Take a look at the code here. We are really looking for feedback here, so fire us an email if you see anything that could be improved. Hope this helps.