Update 2: The site is back up and back to 20-minute update intervals.
Update: Digg sped back up to its normal pace for a little while, then went down completely. API calls and everything are currently down.
For over 12 hours, the Digg front page has moved at half speed. Instead of the normal 10-minute interval between updates, stories have remained at the top of the front page for 20 minutes.