I still think this proposal is too vaguely defined and any effort towards adding async IO support to existing batteries is premature for different reasons, first of which the inadequacy of asyncore as the base async framework to fulfill the task you're proposing.
From a chronological standpoint I still think the best thing to do in order to fix the "python async problem" once and for all is to first define and possibly implement an "async WSGI interface" describing what a standard async IO loop/reactor should look like (in terms of API) and how to integrate with it, see:
From there the python stdlib *might* grow a new module implementing the "async WSGI interface" (let's call it asyncore2) and some of the stdlib batteries such as socketserver can possibly use it.
In my mind this is the ideal long-term scenario but even managing to define an "async WSGI interface" alone would be a big step forward.
Again, at this point in time what you're proposing looks too vague, ambitious and premature to me.
--- Giampaolo