The main problem with bitcoin is that it seems to be more wishful thinking than a serious currency ruled by macro economic factors. There's not a clear correspondence about how the wealth is created and the demand for currency, not to mention that its deflational nature - i.e. its value is always expected to grow- leave serious questions about who'd you invest it, since its value is expected to increase in relation to the investment instrument, so why bother to invest?

I accept that the general idea is not bad, but it'd need to follow some basic standards in order to be attractive to regular people, you don't have to put your son college fund in a currency with no central authority and no convertibility, you can't expect any currency to always perform well so you need options, in case BitCoin start to lose it's value and there's no way to convert that money into Dollars or Euros you'll be stuck with a lots of worthless bits that won't let you buy not even Lehman Bros. junk bonds.