[cd34]

If you can arrange for a little overlap, and the file paths don't change, once you switch the dns things will migrate over -- taking 24-48 hours to get about 95% of the traffic moved.

I would suggest 72 hours just to be sure you don't 404 when the linkbots do their work.

But, you should be safe -- don't try submitting anything during the transition unless you upload it to both accounts just in case you run into a linklist/TGP that has the old dns listing.