Is there any reason to think that Yahoo won't allow an easy way to get this data exported?
Individual account data is exportable from Delicious, but the real value lies in the aggregate data. Part of the frustration around the announcement is that it seems like there would be so many ways to monetize this data, yet Yahoo! didn't appear to try any of them. I think what Dave Winer's suggesting is some way to create a global clone or mirrored data set for Delicious.