We have decided to hold out for the "grace" period which for us is nearly the entire three year period. Reason is that we want to see where QS goes and whether or not 16949 ends up as a target standard for the US and if either/or are going to follow the 9000:2000 structure.
If we were to have to do anything now, we would maintain our current system structure and ensure compliance to 9000:2000 and QS, leaving it at that as I understand it.