Read their blog comments
http://blog.digg.com/post/28441399381/welcome-to-digg-v1
It is impressive how much hate and negativity the comments include. Sometimes we forget that while traffic keeps up community quality can easily degenerate. They will have to put also a lot of effort into community-re-building.
This shows again shows to me how hard and impressive the task is they picked. It's social software. It's not only the rewriting of the software part but also rewiring te social part. Truly inspiring!