I did a post before going to the MVC summit called Do you need work item hierarchy in TFS? which mentioned the new tools from Notion for TFS.

Well there are many ways to skin a cat, and also to produce a hierarchy of TFS work items. Also have a look at Artiso Workitem Manager. This product is interesting as it provides tools that work outside of Visual Studio to manage hierarchies of work items. This might be just what you need for people such as project manager who do not live in a development environment. The nicest feature for me is that allows the import and export of work items into Word document, thus allowing production of specification documents from TFS with the click of a button.