So, a large amount of activity at the level of MNA's acrross the world in getting the ISAF to reconsider.

Sadly, It would appear that the USA is bound and determined to have a keel boat in the olympics at all costs. So not much hope in persuading US Sailing to join the RYA in asking for a change. The risk of loosing a keel boat is too high for the USA.

It would seem that plan B is to break off and form a new international sanctioning body for multi's. How serious is the movement to create a new international organization that would replace ISAF for multihull sailing?

While you can come up with strong reasons for why this would be great.... the reality of creating a real organization and fighting ISAF for authority over multihull sailing will be daunting. Anybody know the players and their game plan for this initiative.