VB experience (not VB.NET) as a prerequisite for .NET could even worse than nothing. Best previous experience would be Delphi (this thing is closer to .NET then anything else as .NET and C# was architected by the former Delphi chief architect
Anders Hejlsberg).
Java and other modern OOP languages are also very useful, more than C++. Knowledge of several languages is a very big plus: there are chances that the candidate learned not so much of concrete languages but computer science, which is much more important. Even more important is the ability to understand, formulate and solve problems which is pretty hard to estimate. If can evaluate it, give it the first priority. General mathematical and/or programming culture is also important, communication skills, espesially written.
—SA