Too early to call? It's hit rock bottom. I've never seen a major site die so completely before.
Digg was a major site that had a surprisingly fast turn of events. There are some good lessons from that.
MySpace comes to mind. Slashdot maybe.
Both before my time. These days it seems like every site is able to withstand pretty much every controversy. Facebook should have died about 5 times by now but the company is as strong as ever.