We have run the test a few times. On our first site the results were very impressive, so we were really keen to know the outcome of the second site.
However whatever we did it always took ages (from starting the actual test more than 10 minutes) and the result was always: no details for the speed up only the before results.
The accompanying video showed the site coming up partially and the optimzed sit never even after the 60 second run time.
The results are to be found here: http://www.webpagetest.org/result/110729_HA_b550413b236a862d476be3d3fe353514/
Clueless at the moment.