We will all be destroyed
 

Serious. See here: http://www.xs4all.nl/~mke/exitmundi.htm

From climate change, nuclear war, asteroids, and black holes to gamma ray bursts, rampant madness, grain, and robots, it's a pretty depressing array of murderous machinations that could wipe us all out.

On the plus side, from what I read, the gamma rays won't be a problem - they're all shooting the wrong direction.

You mean we won't become a planet full of Incredible Hulks?

edit: party hats

I like the idea of the world ending in mass insanity. If you have to go, what's better than going out as a mentally unstable, easily excitable ball of energy? You wouldn't even know it was the end of the world, because you'd be having a damn good time acting like a psycho.