I and a collegue of mine started to change an addin we had written earlier to work with VB.NET. It was real shock to me to find that the VB implementation does not fully implement all the methods in extensibility. Quite a few methods and properties that work in C# project, failed in the VB version. In the end, the small tweak that we planned, became a seperate project by itself.
This makes me feel as if I am not gaining a real advantage from the single IDE stuff. Hope tommorow is a better day..:-)