... the simplest way to answer them would be to clarify that Bitcoins should be treated like other foreign currencies. ... This not only paves the way for Bitcoin businesses and financial services in Switzerland, it is also a great precedent for other countries that look into how Bitcoin should be handled from a regulatory perspective.
Watch out.
Ok, Bitcoin being defined as "foreign currency" in Switzerland might be interesting, because Switzerland enjoys a good deal of financial freedom (relatively to the rest of the world, at least). AFAIK, people there are free to have bank accounts in foreign currencies, use them as they want etc. But in many (most?) places of the world, such definition would be very negative. In many jurisdictions, foreign currency is something "common folk" can barely touch, and when they're allowed to, regulations are strict. Just take Argentina as an example. Bitcoin being defined as foreign currency there would be almost the equivalent of banning it.