The Composite UI Application Block has a very useful feature called "visualisers". It's purpose is to give the developer an overview of what is going on inside a CAB application, which, due to a large amount of various mappings and automated dependencies, could othewise become an overwhelming task.
Great idea - but how about an implementation? Well, there is some documentation (very obscure, just like the rest of the CAB docs) and a single sample visualisation. The sample could be useful were it not buggy: it shows you a treeview with WorkItems and SmartParts in your application, but holds a strong reference to them (or something like that) which prevents them from being disposed. So, in effect you don't get a real overview of your application's state. I didn't know about this bug and wouldn't have noticed it were it not kindly pointed out by the CAB people themselves. But it seems it was too much for them to fix it (strange because the sample visualisation consists of a single windows control).
Or they waited for the community to do it - which at the end someone did. This seems to be the philosophy Microsoft is toying with these days. They seem to want to copy IBM's success with supporting open source projects like Eclipse, but are loath to give anything to open source. Microsoft, like always, wants it all - commercial software supported by a free community. Is the lacking documentation for CAB also supposed to be supplemented by community posts on CodePlex? Come on, people, it's been a year since CAB was released and all we have is a package of hands-on labs and a MSHelp file compiled from XML documentation in the source code.