That ship sailed months ago. If you wanted a big push for uBTC, then would have been the time. Though given that it'd have made lots of normal balances incredibly huge, perhaps it's a good thing that didn't happen. Also "milli" is a unit people encounter in daily life whereas micro isn't. Is it milli / micro / nano or milli / nano / micro? I bet a lot of people would get that wrong.

If you have to export to financial packages that can't handle fractional pennies, then by all means represent prices in whatever units you like for that purpose, but in software designed for ordinary people in everyday life mBTC is a pretty good fit.

 

Besides, fractional pennies crop up in existing currencies too (the famous Verizon Math episode showed this), so if a financial package insists on rounding to 2dp then I guess it may sometimes do the wrong thing in some business cases already.

Lots of people use currencies that don't have any fractional components at all ! So perhaps all prices should be denominated in satoshis to ensure that they're not surprised :)

The (number) line has to be drawn somewhere. Wallets are free to suppress more than 2dp of precision and actually Andreas' app lets you choose your preferred precision. So I think in the end it won't matter a whole lot, if the defaults end up being wrong people can change them until wallet authors catch up.