I see this kind of like when a radio station changes formats. You get angry calls for a week, maybe a few nuts that harrass the station for a month - but it dies down and a new audience takes over.
That's not to say that the new audience will be as large, or that Digg will succeed, however.
Digg has been unprofitable for a long time. Once the VC money is gone, it'll be dead for good.