The Swiss franc is highly manipulated by their bank to keep the value down. Considering they are a touron destination or exporter a high value wrecks their economy. Currently it is pinned at a max of 1.2 SFranc to 1 euro.
Yes, I spent a week in Switzerland this past winter working with what we call a "small high tech" business and they were really hurt by the strength of the Franc, even after it was pegged to the Euro (which I gather is to curb massive asset flight from individuals living within the Euro Zone). Imagine if the peg was not put in place?
As for strength of SGD, I believe it has a lot to do with the economy, their central bank's intervention, and how a LOT of people in Asia consider SIN as a safe haven for their wealth. By the way, the SGD has appreciated substantially against the USD over the past 2 years.
In any case, absent any seismic change, the USD (not Euro or RMB) will remain the world's reserve currency for at least a little longer still.