I think anybody who already filed an I-140 or I-485 will be left as is. But I think some of the family-based people will probably be kicked out of the queue and forced to reapply with points. By tomorrow we should see the details.
However, I think it is unlikely that any CIR that brings significant changes will become law, because whenever any drastic changes are proposed many of the Senators or Congressmen will find something wrong with it and vote against it.
I think the most that will become law is tiny tweaks like exempting STEM degree holders.