Having just perused a few Bitcoin market makers like MtGox, I am concerned that companies which start and engage in trading Bitcoins for fiat currencies, may thereby fall under commerce regulations which would allow governments (like the U.S.) to attack citizens in order to publicly smear this bastion of economic freedom called Bitcoin. Your experience being greater than mine in this new realm, what are your educated guesses or knowledge regarding this concern and how it is being (or may soon be) overcome?
Exchanges are currently the weak links (for legal and other practical reasons) and will remain so until the Bitcoin system is large enough to function as its own economy without major support of capital flows from other (traditional) economies.
Overall, the primary obstacle to Bitcoin's continuation is awareness (leading to growth) - technical issues and hurdles are manageable or surmountable. System D (estimated to be a ~USD$10 trillion unofficial economy, behind only the US ~$14 trillion economy) is a very strong potential arena for Bitcoin's rise to a general monetary tool.
A very possible scenario is one in which Bitcoin (or a Bitcoin-like system) will eventually be used by the majority of the world (beginning with less recognized regions and societies), leaving heavily government-controlled economies isolated. That isolation would make it difficult for most traditional nation-states to thrive. In addition, any method of moving wealth from a restrictive economy to an open Bitcoin economy would be a mostly one-way affair - capital will not return to a hostile environment.
This is a process, not an instantaneous event. It might still occur rapidly, maybe over a period of several years. Established governments and forms of authority simply have no means of stifling Bitcoin or similar systems without either reinventing their socio-economic structures to become more like Bitcoin, or exhausting themselves through excessive expenditures to fight it directly and ultimately failing entirely.