Welcome back, Blake. Excellent thoughts, and I'd be happy to chat further with you about it. It seems like something like this would do well to start off as a contrib that we can roll into the core package come D6. I haven't had time to investigate SimpleTest much, but I'd be happy to lend some effort here when the time comes. Feel free to start a separate thread when you know what sort of helper functions would be useful, and we can pitch in.