No way.  Non-determinism in the trap that we're trying to get away from.  As soon as we introduce non-determinism into the tests, we stop being able to trust them, because we keep tripping on things like this.

Overnight, I realized that we do need to do better than just leaving this stuff hanging around, and I agree with Mark/Niko's new Should on the user story.

My current thinking is that a good way out of this is to add an app.terminate() that terminates everything forcibly, rather than clearly, and thus doesn't requite a callback.