I think one of the core assumptions underlying people who adopt Bitcoin is "Inflation is bad". I'm no economist, but I don't think this is always the case. Currencies being able to rise and fall relative to each other allows governments to stimulate the domestic economy by increasing the value of exports, or cool down an overheating economy by doing the reverse.

Meanwhile, there are some other basic features of the currency which seem undesirable to me. In particular, the built-in (and ever-increasing) scarcity of coins means that the value of the currency will always, continuously, rise. That seems great, except that an economy built entirely on Bitcoins would therefore have an economic disincentive to investment -- if you can make 5% return by just sitting on your coins, why would you invest in a new business and create jobs and risk getting less than that?

Bitcoins do seem pretty attractive on an individual level, but at the macro scale they worry me, and I'd love to hear somebody with an economics background chime in on these points.