I actually called the IRS and asked about having to be registered as a money transmitter.
There response was that ANYONE who buys, then re-sells, etc IS A MONEY TRANSMITTER AND MUST FILE IF EXCHANGE OVER $1,000.
If you report your BitCoin income, then audited, and not registered you will be in trouble.
You're talking about something different. The IRS is not FinCEN.
Registering as a money transmitter is necessary to comply with anti-money laundering and other regulations.
Income and capital gains taxes is another matter.