To be "honest", "different" here means "almost identical to historious, diigo, evernote", etc. There already are plenty of players in the space, but delicious has spoilt users enough that they don't want to pay for these services.
Also a noticeable difference from all these sites is that I when I go to delicious.com I immediately see what it does (bookmarks). All these other sites have a landing page to explain how they've made the simple process of saving links online more complicated.
Any one know who the team is?