I've been reading all the posts/flames/etc, regarding DNN C#, which, of course, does not exist. I understand the reasons behind selecting VB originally, and why it is still that way today. I'd like to add my 2 cents to the conversation.
In my experience, C# is a bit easier to maintain. This could be due to my background (C++, Java, among other OOP languages), but I've noticed for large scale projects some languages seem to just be easier to deal with. I have to admit, when I code VB, I usually have language syntax reference on speed dial, but it always seems like more work to do a large project in VB (opposite in small projects, though).
What a pain it would be to translate the entire site to C#! I have always wanted to contribute to the core DNN project, but wouldn't consider it in its current VB.net implementation. It gives me headaches just thinking about it (and nightmares if I would actually be doing it...).
That leads me to my next point. MAD PROPS to the core team for pulling off such a massive VB application that is still very performant! Wow. Mad skillz!
Anyway, here's my idea. It's a matter of time before we see DNN for .net 3.0. Wouldn't it be great to have a total rewrite in C# for 3.0? I'd definitely pitch in where I could! I'd love to see some of the cool features of 3.0 implemented in DNN (especially voice activated website! wow...). I know a massive project like this is very difficult to manage, and trust the core team to deliver the best possible solution, in any case. Besides, the project is great as is, and I can use C# for my modules, etc. I believe there are tons of developers who would contribute more to the core project, however, if it were entirely in C#.