I find this hard to believe... mtgox, bitcointalk, bitcoincharts were all just experiencing "too much traffic" today?
bitcointalk has a massive donations budget, and we all know mtgox has a lot of money and a huge interest in preventing something like this from happening.
I think it was a DDoS combined with a few opportune sells to create a panic on purpose to be quite honest.
Tinfoil hat replies welcome.