From zerohedge:
Is a person who “mines” a virtual currency considered to have received income?
Yes, and if the taxpayer engages in mining as a trade or business, self-employment tax is often due.
This is going to be a problem.
Bitcoins are fungible and globally mined. If a US company issues “Equity/Stocks” is that a taxable event? I don’t think it is.
I agree. I also agree that "mined" coins are a source of income, just like any business. I see the possibility that miners will have to be regulated now, or somehow a record of the "BTC" they produce maintained.
Issues that will need to be worked out in time as will all new technologies. There was a times when didn't need red lights or even parking meters. ;)