I don't want to imagine the chaos that would unravel. cars on fire, TV's through windows, buildings exploding... It would be the start of the end of everything as we know it.
December 21, 2012 will be the end of the world because MLP:FIM gets cancelled. In all seriousness, nothing will happen!
Cats and dogs living together, mass hysteria! I imagine a 2nd or even 3rd season woul not have happened without bronies. MLP at it's best has never lasted more then a season. But they are now trying to stop viral marketing, goodbye 4th season.