tl;dr No. IANAL.
If you mine Bitcoins, you hold them. If you want to exchange them, you can give them to someone in exchange for dollars (in which case the exchange is an MSB and is subject to the rules for money transmitters) or you can give them to someone in exchange for "real or virtual goods or services", in which case you're fine, or you can hold them, in which case they don't care.
On the other hand, if you happen to mine some coins and then set up a lemonade stand in front of your house where you sell those coins to somebody in exchange for real dollars, then you are a money transmitter according to the guidelines.