Just had a chance to see an internal demo on the TFS reporting and data mining type features.  The walkthrough included using Excel pivot tables and integration into OLAP cubes.  It was all hooked into our dogfood TFS system so the data being reported was live stuff with names we recognized showing up on the 'top 10' lists.  It was as ugly as dogfood ever is (the dev kept saying "we fixed that in the post beta 2 branch"), but with mastery of how to think OLAP and query into the data there is just awe inspiring amounts of insight into what's happening.  Having been the man behind the curtain on more than one home-brew database backed internal 'test results' server for QA groups I've worked on, the possibility to have this type of reporting tied into everything and in a shipping product is definitely exciting.