Last week I finally took some time and build a version of my Pipeline Testing library that can be used in Visual Studio .NET 2003 to test BizTalk pipelines and custom pipeline components in BizTalk 2004. However I am not releasing it right now, as the current version is slightly limited in functionality compared to the original BizTalk 2006, though it's very usable as is for most purposes.

I don't have the time right now to spend bringing it up completely to the same level, though hopfully in the future I'll be able to do so.

So, if anyone is interested in it, for now, leave a comment or send me an email and I'll send it over.