Someone asked about this on one of the Ebay Ink Blogs and this was the answer that was given. I still don't understand how this is gonna work though.
5. How will listings submitted through a listing service like Auctiva be handled?
Third party services will continue to work for our sellers. At the time you need to authorize, aka “Auth&Auth”, a new or existing service, you will need to need to be on a recognized computer to be able to grant that authorization.