I was going to say basically what Alfred said, but didn't want to assume too much as it's been a few months since I did any .NET development.
The strength of .NET, and the reason I switched to it was the multi-lingual capabilities.
In fact, when our team (at my last job) first switched we had one J# guy, a C# guy (previously C++), a VB.NET guy and a guy who used Borland's Delphi extension.
It worked great. Over time everyone switched to C# for standardization and ease of documentation (I also 'pushed' them a little because I dind't want to have to maintain a J# position). But, everything always worked great together.
It's definitely one of my favourite things about .NET, because it eliminates most people's biggest fear: learning a new language. They just need to learn the Framework (and the IDE, but VS.NET makes both of these incredibly easy).