Whether you prefer C# or VB.Net for Revit API add-in development is probably a matter of preference. So for those of you who haven’t heard yet:
Based on popular demand, we have now added new VB.NET samples.
So regardless whether you are new to this training or have already gone through it once with the C# code, now is your chance to choose the language you prefer, C# or VB.Net, at www.autodesk.com/myfirstrevitplugin.
via
The Building Coder: My First Revit Plug-in in VB