I will be speaking at SharePoint Saturday - Ozarks in Harrison, AR on July 18th on SharePoint Architecture: SharePoint Capacity planning and performance (the labs). http://www.sharepointsaturday.org/ozarks/default.aspx.
We will take a deep dive on how you can stress test your SharePoint environment with the already available Visual Studio Tools. We will also look SharePoint Capacity planning tools. See you there!