Regulations came out yesterday regarding taxation of Bitcoin. The short version is it’s to be taxed more or less like a capital asset, subject to the usual rules on capital gains. Reuters found a few Serious People who say this is going to put a damper on Bitcoin mining, but given the amount of processing power that currently goes into one block, that might be a good thing.
No actual users of Bitcoin were consulted.
EDIT: Here’s the actual guidance. (PDF)