Team Foundation Server Reporting and Visio
Visio 2007 has some very cool new reporting features. I'm very excited about the the PivotDiagram features in particular. PivotDigrams can be used to slice and dice data just like Pivot Tables in Excel. Here's an example of a Visio report that shows the active and resolved bug and task distribution across a number of projects on a server.
And, here are a couple of videos that walk you through writing these reports.