Who else is going to be there?

I think the current meta (I call it 2.0) for short is well suited for a number of
issues pertaining  to day-to-day operations and to the SE interface, and 2.0 is
ill-suited for the long term discussions that need to take place to keep
MathOverflow the idea going.  However, if there is only a small group
interested in using Discourse, then I recommend using the old Vanilla forum,
with someone updating 2.0 periodically with a summary of goings on.