My $.02 on why C# devs make more $
First of all let me say that most salary surveys are blatantly wrong. But for this exercise we will assume these assessments as truth. C# developers on a whole make more because their skills sets tend to be more multi-faceted. I don’t know of any C# devs who don’t know VB! By virtue of the fact that they are comfortable in c based syntaxes, chances are they know C,C++ or Java. They tend to have a wider range of experience and much smaller learning curves. (this is demonstrated by the fact that they are working with such a new language and framework.) The simple fact is that C# developers make more because they tend to have more experience (in general) than their VB counter-parts. Not because C# is better, or tougher.
Another thing that comes into play is the simple economic factor of supply and demand. Many more VB guys out there than C#, this is complicated by the fact that the IT decision makers have some how gotten the idea that Redmond is phasing out VB and moving C# in so they in turn need to get on that bandwagon.
Finally, C# guys make more money than the VB guys because we are far more handsome!