Back with Beta 2 it was found that Microsoft had set the refresh rate for the reports and data warehouse at 2 minutes.  The appropriate setting to avoid having your CPU thrash is about an hour.  As I explained in my May 2005 article this issue is more fully explained here: http://blogs.msdn.com/buckh/archive/2005/04/19/409886.aspx.

The Beta 3 Refresh of TFSMicrosoft resolved this issue.  In order to verify this I went to the service.  Note, under Beta 3 Refresh the controller service has moved slightly to this url: http://localhost:8080/Warehouse/v1.0/warehousecontroller.asmx.  Once at this url you need to access the 'GetNextInterval' method which accepts an integer.  Pass a 1 or 0 or whatever, and the service will return your servers updated interval value.  My experience is the current default is 3600 which is the correct value.