How many of these countries have laws relating to financial intelligence that will make a completely anonymous form of currency illegal to implement? Large companies simply won't be allowed to accept a large quantities of money from anonymous people - it's too perfect for money laundering and parent has a very good point here. Perhaps there's a real opportunity here to start architecting "non-anonymous bitcoin" so government's needs for financial intelligence is appeased.

That being said, there there's still monetary policy to consider. In South Africa, for instance, I suspect Bitcoin would face legal challenges given the strict monetary regulations imposed by the Reserve Bank. Somebody earlier in the thread mentioned MPESA - a mobile payments solution in Kenya, which is also available in South Africa. MPESA grew quickly but growth has a ceiling because it cannot be used for business-to-business transactions, or even for a very class number of business-to-consumer transactions, as the transaction volume limit imposed by the Reserve Bank in these sorts of schemes makes it feasible only for individuals to use.