Why not go back to the drawing board and build a better version of delicious? Surely the non-compete has already expired. If he comes out with a new delicious like product, he'd get a ton of press because of the whole "he sold, and his product was ruined, now he is back where he left of, " angle. So he'll have his big popular website again and a ton of money in his pocket.
http://pinboard.in/
http://news.ycombinator.com/user?id=idlewords