Tax tip from a non-lawyer/non-accountant - Immediately sell a percentage of your newly mined bitcoin equal to your marginal tax rate. If your tax rate is 25%, sell 25% of your bitcoin as soon as it is mined. Those coins already belong to the US government. If you don't convert to cash immediately, you are basically leveraging the government's money to invest in Bitcoin speculation.
If I have accumulated $100,000 in capital losses over the prior ten years, I can wipe all of that out in one shot by producing a large enough capital gain in one year.
Capital losses saturate when applied to ordinary income.
This is money, not "do whatever you want".
That said, it doesn't matter what is and is not "fair" when dealing with the IRS. Choice A is to do what they tell you to do. Choice B is to fight them in court.
This thread assumes you want to go with Choice A and that you want to limit your liability if something goes wrong. Like most risk-management techniques, it does decrease your returns.
(Tax lawyers might have some better advice. Perhaps you can mine into a blind trust, and pay income taxes in 5 years on the current value of the coins? Dunno, not a tax expert or a laywer. I would consult with one if I was mining a lot of Bitcoin.)
"Bitcoins earned through mining are considered compensation for providing resources to the Bitcoin network to compute hashes verifying transactions."
When viewed as compensation then the treatment seems consistent with NSOs or barter transactions.
They make allowances for things that are not liquid.
i.e. would sales inside MTGox have counted towards this tax or isn't only with withdrawl/deposit into their ecosystem. I can imagine that if internal to MTGox interactions are treated this way then there are a lot of people who sustained a capital loss higher than that and had no option to withdrawl the money to pay taxes.
I disagree wholeheartedly. The tax code is needlessly complex. These are not laws of nature, they are arbitrary rules that have accumulated over time. Large capital gains happen naturally and it's silly for there to be gotchas like this.