Don,
I guess there are two kinds of 'private'. Will the core team have a 'private list' so that all core members can keep up-to-date in a simple way? Then the kind you gave an example of where one member just wants to nudge another member to look at something. Maybe the comment from Lars would be done on the private list.
It might be helpful if all substantive discussion could be followed on the private list. If emails pass between a Core member and a community member, maybe the private list should be cc:d, so that when decision time comes, no time is lost trying to give the gist of how the decision was made to the other Core members.
