Paul Newton, you legend! That was exactly it, all I need to see was that one little thing.
Originally when I followed this tutorial, I didn't know where "MFDeploy" was coming from so I googled it and downloaded it from Microsoft. Watching the video you recommended I noticed that the guy was running MFDeploy from his MF4.2 installation!!! That was the Key.
The standalone MFDeploy didn't see my Netduino. The Version that's bundled with the Micro Framework did!!!!!!! I'm up and running again.
This not withstanding, I did still have problems with SAM-BA running on Win7.