Look at Bulgaria. In 1997 the Bulgarian Brady bonds were the best-performing Brady bonds in the world because this little country went to a currency board system. In that sense, this will be even more of a benefit for the poorer countries than it will be for the richer countries. It'll lower their cost of capital. Of course, those screwball local currencies prevent capital accumulation in these countries.
People save and inflation confiscates the savings.
Money will flow in response to investment opportunities and not in response to rumors of devaluation and speculative flows. As I see it, currency unification is an optimistic scenario. The last time this happened was in 1982, when the Garn-St. Germain Act repealed old regulations and allowed savings and loans to graze for investments in areas like real estate and mineral development. No one yet knows.