OK, it has been a couple of days and the general consensus seems to be a 'rolling' two-week window, with no "below 20%" rule.
I don't think there is any need for a two-week email discussion period among those familiar with the guts of Bitcoin, we've already spent months discussing the options and the consensus for BIP 16 is clear (see the tally here).
It is time to call it settled and move on to bigger and better things, like what protocol to use when a client needs to gather signatures (REST? JSON? http? https? something else?).