I would like to point out a few things this thread is omitting.
1) I do not know why anyone would be surprised by the ruling because it is a limited-supply digital commodity AND digital currency. Read "digital" as "better" in terms of ease of exchange, as merchants get on board. There was never any reason to think that it would not be treated like any other commodity or FOREIGN CURRENCY subject to normal capital gains. The IRS publishes an official December 31 exchange rate on all currencies so that you can calculate your capital gains. Currencies are commodities, subject to normal supply and demand rules. The only difference is that your government defines which commodity (currency) you must use to pay taxes in and therefore if you have capital gains or not (none in the case of the asset/commodity we call "dollars"). We used to pay taxes in silver, a era commodity that was historically also called a currency. The best currency is the commodity that can't be counterfeited, can be easily transported, and changes the least relative to a basket of the most common commodities so that true economic value remains unchanged since traditional commodities (physical or energetic as opposed to currency) are the fundamental inputs to society.
2) Therefore the IRS has declared bitcoin is the same as foreign currency.
3) I do not know why coindesk wants to keep slamming bitcoin over this *expected* tax clarification without any rational consideration, discussion, or explanation.
4) The current drop is partly due to people selling in order to pay their taxes. I am sure MANY bought below $200 sold a largish portion above $1,000 and therefore they are paying 50% taxes in terms of late-2013 bitcoins instead of 25% because the coins are now worth less than half of where they made the profit. For example, if you bought 100 bitcoins "early" last year at $100 and sold 50 at $1000, you have $45k in short term gains, and used the money for something else. Today they would have to sell 25 coins to pay the taxes, a 50% tax rate in terms of bitcoins. I'm holding at least until a few weeks after April 15.
5) If a miner declares it a business, he owes 15% social security/medicare in addition to 33% in federal income taxes (48% plus state taxes) if he made a substantial amount. I don't know if he can do it, but it would be good to call the expenses a loss on the capital gain investment (cost basis) and get the 15% rate instead. The only other way to lower the 48% is to declare it treatment like a C-corp with dividends and declare a low "salary" to get the self-employment tax down. Or start a SEP IRA for the business and lock up to 20% of the profit in the IRA and not have to pay today's taxes on that portion (but taxed when withdraw at your "retirement" tax rate (without SE tax?). Then don't forget you have to pay for your own health care and in some places your children's education to get something decent, and you can't really expect the social security retirement to ever come through, whereas normal countries offer these things in exchange for a similar tax rate. All military-dominant societies like the US collapse like this: by using an excessively strong currency and debt structures (IMF/world bank) to force other populations into excessive labor and getting access to cheap commodities. The colonial slaves (Asia in our case) become the only experts as the empire citizens get too lazy. The slaves then can make better deals with the commodity producers (S. America, Africa, Arabic oil, and even Australia) so that the empire's currency is no longer able to get cheap access to even the commodities even if it tried to produce things again.
6) If its dollar value does not change there are no taxes owed. Why is coindesk acting like making a PROFIT from doing nothing and having to pay taxes on it is a death blow to bitcoin as a currency which is not supposed to be increasing in value? Even the sting of a loss on bitcoin is reduced by the tax deduction. If you are willing to take the risk on it losing value, there is nothing new here except that the IRS has made the obvious and expected definition the rule.