Paul Gauthier and I were talking about using more of the information stored in the Team System data warehouse for the "inspect and adapt" aspects of most Agile practices. If you use TFS for managing your Product/Sprint Backlogs, associate source control changesets to Sprint Backlog Items, and use Team Build then you have a wealth of information about your process at your fingers. There are some great reports out of the box with the Conchango Scrum for TFS process template, but there is so much more data to be mined.
Paul's team is just starting with Scrum and we have had many conversations about estimating User Stories in the Product Backlog using Story Points. Most of the groups I coach have to get used to the idea of estimating this way. I always tell them that over time your team will become more accurate with gauging the story point value of individual stories. We talked about being able to go back over time and see how many hours were actually worked against individual stories and using that data to get an idea of how much diversity there are in the actual hours worked over multiple stories assigned the same story point value.
Paul created the great report we are calling "Product Backlog Estimation History". You choose a story point value and a date range, then the report will show you a graph of the number of Product Backlog Items with the same amount of actual hours worked.
Over time you can see trends in how accurate your team is estimating using story points by seeing the variation of hours actually worked. If you see a large variation then you might want to look at this during a retrospective to see why the estimates are no more accurate. You will see some degree of variation naturally, but large amounts can be a symptom of a deeper issue.