While not trying to start any sort of flame war here, I agree with MexicanCustard. I started with VBA and later adopted C#. All of his points are valid about VB / C# and I would add the the vast majority of open-source .NET code and samplec is in C#, most architecture discussion leans on C# / C++ style languages. Consider it like speaking English, you're have an advantage if it is your first language, you will get a lot of value from understanding it at all, you are at a severe disadvantage if you don't understand any of it. Personally, I find VB quite wordy compared to C#, I can read C# much faster than VB (and a lot faster again than Lisp).
THe WinForms / WPF argument is a little less clear-cut but I also concur here - the learning curve for WPF is somewhat steep but I think it is/was worth it. The WPF paradigm is also more like the paradigm for building web apps, at least a lot more so than Winforms. The real trick with WPF is to build an application that can run without the UI, only then you will know you have really separated your concerns. The application logic drives the UI (via binding), not the other way around. Why is this a big deal? Easy example: your application can run in the Core Console with minimal changes just by leaving out the UI, you can't do that with an application where all the logic is in code-behind classes. Your application could run as a web service on Autocad.IO, also with minimal changes.
My app in a palette in the screenshot at
http://www.theswamp.org/index.php?topic=49267.msg543726#msg543726 (not RegexBuddy, the bottom one) is WPF, it also runs in the Core Console by presenting its functions as Lisp methods and has a public C# API so I can call it from other things I write, I literally just left out the UI to create teh Core Console version. Also, by doing this I can port it to IntelliCAD, BricsCAD, NanoCAD etc quite easily. By really separating all my concerns (and programming against Interfaces) I can also potentially port it to a completely different application (Excel, for instance). That's a bigger change but it's a migration, not a rewrite. No, I haven't considered it. YET.