Agreed. If there is a demand and especially if people are willing to put up a little BTC for it then I'm sure programs will pop up to pull the exchange rates and help do the needed calculations.
You aren't getting it. Let me do an example:
to make it easy, lets keep fractions out of it. I mined 1 BTC yesterday, at a price of $550
I then mine 1 BTC today at a price of $600
I then mine 1 BTC tomorrow at a price of $650
Do this for 1 year.
I then sell 1 BTC. Tell me which BTC I sold. Was it a loss? a gain?
Where are you going to track exactly which coin was sold...especially if they're all partial coins (.25, .50, .25)...
I'll save the suspense...you can't track that.