I hardly use Digg so I won't comment on the change. But I once spoke with founder of Webjet David Clarke and he told me the story that there was one time Webjet

I hardly use Digg so I won't comment on the change. But I once spoke with founder of Webjet David Clarke and he told me the story that there was one time Webjet replaced its old travel search engine with a new "statistically proven better" one and on the day of change its web transactions literally stopped. This was because the user experience was so different that people were instantly turned off by it. Webjet had to switch back to its old engine the next day and transactions took off again. I don't mean founders shouldn't improve or iterate their sites, but do so "evolutionarily, not revolutionarily" (David Clarke's words). So (without analysing the specific items) to me the long list of changes made to Digg doesn't seem to be a good sign - are the users just going to say "no this is not Digg, I don't like it anymore"?