In case you didn't know, GotDotNet is shutting down. I recently got an email asking about my very old DevHawk Wiki project, which had been hosted on GDN. I didn't realize anyone was still interested in this project, so I set up a new project for it on CodePlex. As part of the move, I decided to rebrand it "HawkWiki" and change its license to Ms-PL. (CodePlex doesn't support the zlib license DevHawk Wiki was originally released under.)
I uploaded two versions to the HawkWiki source repository. The version that until recently was hosted on GDN is version 0.2. There's also later version that I never publicly released before. This later version compiles the wiki markup text into an IHttpHander class, similar to how ASP.NET compiles web pages. I'm not sure if you'd ever really want a wiki built this way, but it does provide a good example for building your own compiled web page infrastructure. If you ever read my old MSDN magazine article, you'd know this is an approach I've been interested in for a long time.
I also used this project as an excuse to get to know CodePlex. Though CodePlex can integrate directly into VS via Team Explorer, I chose instead to use the CodePlex client. CPC provides an edit-merge-commit command-line experience like Subversion. I found it much easier than using Team Explorer, though adding new files was troublesome since they had to be added to the project and source control separately. If you like this approach, there's also a version that works with vanilla TFS instances (CPC is hardwired to CodePlex).
So feel free to take the wiki code and mangle it to your heart's content. If there's interest, I'd be willing to grant some other folks checkin permission. However, it's more a curiosity than a real project, so if you're really interested in a .NET based wiki, there are better choices out there.