Fantastic idea, been looking for a replacement for Rogue Amoeba's "Detour" for years. Just want to route audio, don't need volume adjustment or EQ.
Unfortunately, this doesn't actually work. Installed it, only a subset of audio-generating apps show up. Deleted, reinstalled, and now a larger subset shows up, but still not many of them. Most importantly, not iTunes.
Enormous potential, but it has to actually work.