The original forum post about these proposed changes (April 2010) is here:
We have been working with NSCT to ensure that OSCs can plan ahead, so that any arrangements for scrutiny of the proposals is effective and efficient, especially in the current economic climate. It is also important that OSCs do not take up valuable time during the consultation period deciding on the practical nature of the arrangements for scrutiny.
At one stage it looked like a national joint OSC might be a possibility. However, in light of the arrangements for 'regional' joint scrutiny that exist in many areas it now appears that NSCT could consult with relevant OSCs on that basis rather than nationallly.
OSCs will need to decide whether the proposals from the NSCT are 'substantial'. They will not be able to do this formally until the proposals are published (in October). But, from the information available from NSCT about the 'case for change' OSCs should be able to discuss informally now in preparation.