RodeoX, I think you are overestimating the computing power needed to take over the block chain, and underestimating the threat that BTC poses to the established financial community, both fiat currency providers and credit card/POS issuers.

The current hash rate is 63.686 THh/s, and a production mining rig does 50 GH/s. So with a mere 1200 commercial rigs, the entire current hash rate can be duplicated.

Do you think that these established players will let themselves be brought down when the cost is so small to bring BTC down?

BTW, I am an ASIC designer by trade, and have worked on the most powerful computers, used by Livermore Labs. I know what I'm talking about technically. It would be trivial.