I haven't been following this as closely as others (primarily because I was never a heavy delicious user), but was there a lot of pressure on AVOS to push out the new version as quickly as possible? I find it hard to believe that a company would try to relaunch a product without transferring a good amount of the historical data that makes it so useful.

They should have taken their time and gotten it right. You only get one chance to make a first impression.