We completed our certification audit last Friday. We received four minor corrective action requests, all of which are easy to correct. Our CAR responses are going to the registrar today and we should have our ISO9001:2000 cert in hand shortly.
It wasn't that difficult a transition all-in-all. Our documentation, such as the quality manual, was revised to make it easier for the registrar to audit to it.
We had to clarify some things, but much of the requirements of the standard was already implemented so it was mostly updating the documents to show what we do in compliance with 9K2K.
Overall a pretty painless process.
But the registrar did say they were expecting quite a rush come this time next year so it may prudent to transition sooner if possible.