I've love to hear what this means for realtime multi-channel audio applications. Would someone close to this give us a summary, or recommend some resources for the only-barely-knowledgeable?
Regarding audio, I currently use some tools from Rogue Amoeba called SoundSource, Loopback, and Audio Hijack that allow users to redirect, record, and add effects to virtual audio devices and applications on the system. Currently, it's installed as a kernel extension, but I'm not sure if it will be possible for it to move to the new framework.
I know they are having a dialog with Apple about what's still lacking for them to do it the new "right way" but I think for now you sill have to basically do what Jason outlines.