From what I can tell, it looks like you are trying to target the 4.3 Micro framework version instead of 4.2. Under the project properties, switch the version of the framework from 4.3 to 4.2.
Another thing is if you are staying at 4.2 (which is recommended at this time), I have found that both the Netduino 2 and the Netduino 2 plus deploy/debug works much better in VS 2010 with the latest 4.2 Netduino SDK compared to 4.3 SDK in VS 2012. I have gotten it to work but it seems to hang after the 2nd or 3rd deploy/debug I would have to disconnect the Netduino from the PC.