As I continue to cleanup my projects on CodePlex, I've posted the latest version of the source code for my SharePoint Forums Web Part. This is version 1.2 that was released in August (better late than never?).
If you're interested in contributing/enhancing the project please do so. Right now I'm juggling a bunch of projects with lots of team members so it might take some time to get you added to the team if you're interested. If you are interested in modifying the codebase then Scott Hanselman has a great blog entry here on creating patches. You can simply submit a patch file to me (via email) and I'll add it to the codebase. This way you don't have to sign up for a CodePlex account and go through setting up all those tools. Your choice but please consider contributing to the project.
The source code does not include the 2007 version as that will be released under the Community Kit for SharePoint project (CKS) which also lives on CodePlex (surprise surprise). I'm donating the 2007 version to CKS but in reality just simply having it hosted under that project. It'lll be the same Web Part however hopefully we'll have some more bodies working on it under CKS.
You can download the source code directly from here (sort of direct since direct file links don't work anymore on CodePlex) or through a TFS client (Teamprise, Team Explorer, etc.) if you're signed up on the site via the latest change set here.