No, I'm not arguing. No need to argue. I've agreed to Jeff's terms (aside from the money), and am clarifying/adding some of my own. ;)
He said C# or VB.NET. Those are the two primary language choices. VS.NET is the IDE for building/debugging .NET apps. You can use C#, or VB.NET, or both (i.e. you can write some assemblies in one language and one in the other). The languages, the .NET runtime framework, all the namespaces, etc. - those add up to .NET.
.NET provides support for mobile devices through the .NET Compact framework.
Kevin