What happens if the NSA decides to trash the whole game by ramping up their super computers for a few weeks or months doing solo mining thus increasing the difficulty to impossible levels then dumps their coins on the market as well thus dropping the bottom out of the "value". This is where I see the flaw in the whole Bitcoin thing and that is any one person or Gov't could with enough resources totally trash the Bitcoin economy. Hell Warren Buffet could build a T/h minig operation with what he spends on two suits or dinner.
I think if they did something like that people would notice it first. They'd see the mining volume move way up and they'd see the wallet accounts the bitcoins were being sold from. I think if they tried it, many like me would see it as a terrific buying opportunity. They would be doing all that mining at a terrible loss and selling the bit coins at the same time which would be a great service to bitcoin. Ultimately the purpose of bitcoin is to produce a viable currency for trading and buying- not mining and speculating. They would just end up furthering that goal IMO. Not that it wouldn't make things extremely volatile for a while, but volatility makes for profit opportunities too. At this point everybody expects volatility, if the coins were made legitimately (and they would be legitimate in you scenario) many people would just snatch them up and say YIPPEE!