> Is this based on the flexibility of C#?

It's based on a number of things.

1. If VB is the cat's meow and VS combines all of the languages into one IDE, why bother to create another language?

2. C# and VS.NET were designed simulataneously. Coincidence? I think not.

3. VB as a language sucks and always has. People use VB for the tools and VB's capabilities because VB has always had great tools and could do a lot, but the language has never enamored me.

4. The constructs, syntax, names etc. in VB.NET are poorly chosen.

5. Most of the sample code in VS.NET is in C#, not VB. Message?

6. The VS.NET framework is in C#, if I ever need to understand the framework itself to the point of having to look at the code, I'm going to need to know C# anyway.