That's a fascinating article (thanks Brent for posting it) which raises many important questions.
One thing that stands out in my mind was an "unofficial" comment made by an anonimous BOC official. He said that we should expect to see series of notes be revised every 5 years, or less, as printing technology improves. In other words national banks will always strive to stay ahead of the counterfeiters. To know that wayward countries, or anti-American billionaires, could be at the bottom of such illicit activities, seems to suggest that future governments, treasurers can't take anything for granted these days.