No, it's not a joke! Its been 8 years since the DotNetNuke project forked from IBuySpy in December 2002 by Shaun Walker, the founder of DotNetNuke. The DNN Core has always been VB.NET and you can read the reasoning behind that from the official DNN Blog along with Shaun's explanation for the change.

In seems recently that a greater emphasis on the C# language in the .NET ecosystem. Tooling is a glaring example. In switching to C#, DotNetNuke Corporation believes its developer community will benefit from greater access to development resources, source code examples, and enterprise acceptance.

I simply would like to say I'm glad. I'm not overly excited or "giddy", because I rarely "peek under the hood" anyway. I first started learning VB v4.0 and progressed from then. When the .NET languages rolled out I pretty much stayed in the shallow end of the VB.NET pool, all while feverishly learning C#. Since then C# is my language and what I feel will be the choice of many as it seems to be Richmond's choice as well.

I'm glad that DotNetNuke has taken this course. The ability to find good developers just got a lot easier.