I agree that it's disappointing that the article didn't mention reddit, but the compete.com data doesn't exactly support the notion of digg users flocking there:
http://siteanalytics.compete.com/delicious.com+digg.com+redd...
http://siteanalytics.compete.com/delicious.com+digg.com+redd...
I guess thats what you for looking at a website that pretends a 1% sample is representative of actual Internet usage for anything beyond painting the most board strokes.