According to Palm Sounds, an Apple insider has confirmed:
"there is no feature in iOS 6 that can be described by the phrase 'inter-app audio'"
This corroborates what I reported immediately following WWDC:
Apple sacrifices unbaptized babies, kills Audiobus!
There was a resurgence of murmuring about this yesterday, among developers. Including some choice Tweets from Tempo Rubatos developer, Rolf Wöhrmann.
"I can only tell: Don't believe everything some big companies write on their slides ;-)"
"the multi is there, the inter won't come."
The "multi" he is referring to here is "Multi-route audio", another tidbit we got from Apple's WWDC slide. What does that actually mean? And what does that actually mean for apps? We'll have to wait to find out!