Virals are getting trickier to figure out, that 'one night stand Danish girl with baby' from a while ago I called immediately and I got nothing but flak for it, that one turned out to be on the money, not having a clear beneficiary does not seem to be a hindrance.
The basic formula is still the same: every viral video has to be either funny or urgent. It's just that executing is harder because there is more noise. So while it's getting harder to predict which videos will go viral, you can still do a pretty good job of predicting which videos have the potential to do so.