brusma did a thread about human extinction a couple of weeks ago, but it was a bit of a joke. This is more a miserable/angry/accepting-we're-all-horribly-fucked-probably-within-our-lifetimes one.
I just read this essay, it's pretty depressing, starts talking about suicide as an act of altruism and stuff like that http://guymcpherson.com/2013/04/the-irreconcilable-acceptance-of-near-term-extinction/
Feel free to use this thread to talk about stuff other than human extinction if you feel like it.