I do not really use them (I have only tested them), but this is the main reason to support it.

Actually I think that for a future system the currency question is no longer relevant. With fast, and almost commission-free electronic exchange systems, it doesn't matte what is used as the currency - you can exchange immediately your personal "currency" (which would be reasonably based on obligations to give you real values) into whatever is used for exchange.

But if it is bitcoins, that would be fine.