In reply to alexm198 & BarneyLoosemore:
Sounds to me like you're disagreeing about the definition of nihilism. The sense which it's used here is the sense that I understand it: the universe simply *is*, and it has no purpose, there is no 'other realm' of moral principles or religious truth or spiritual connection to the cosmos. I'm guessing that nihilism has a more specific/formal meaning in philosophy, which as you say is not what the video's talking about.
So, the existentialist philosophers came to this position before we understood the *big* causes of existential angst outlined in the clip: the unimaginable scale of the universe and our insignificance as cleverly assembled clumps of molecules in it (although I totally agree with the idea that life, and particularly consciousness *does* have a type of significance in the universe, just not the ridiculous "centre of god's creation" sense). Good on'em!