At the risk of sounding like a negative-nancy the problem he is fixing is the artificial impedance mismatch that was constructed ON PURPOSE by Ian Bicking when he created WSGI.
Composability is one of the most powerful concepts we have. WSGI wasn't mistake-proofing middle-ware by making the protocols different, he was breaking composability that is now being fixed by Kenneth et al.
Thank You! But let us not allow these mistakes to be made again.