As noted in Ed Glas's blog dynaTace has just completed a nice integration with VSTS web, unit and load tests that enables them to do end-to-end tracing of performance. In addition to getting overall performance numbers, they have a feature called PurePath that let's you trace, down to a given web test request, what calls that request results in on the mid-tier and data-tier.

 Check out the two minute video when you have two minutes: http://www.dynatrace.com/twominutedemo/default.aspx

 Terry