I believe for the 2008/09 season, the decision will be affected by how this one goes. As well, there may be another push to modify the format of Div 2 to align it with Div 1.
I believe Bonefish is right. the final setup will probably include 20 team divs 1,2 and 3 with a Premier that is 12. The setup is for one year until things change again the year after.