Since we started the SharePoint Guidance project, I have heard from most customers that they do not unit test their SharePoint projects because it is hard to do. In our drop that will come out tomorrow or Wednesday on Codeplex we have some good content on how to unit test applications built with SharePoint. This guidance started with a recent blog by Francis Cheung.
Check out the blog and the CodePlex drop as it is quite useful if you are trying to understand how to unit test SharePoint Applications. Let us know your thoughts on the guidance. Is it easy to understand? Will you use in on your current or next SharePoint project?