Stress test is a fun:) I even wrote an article about load testing using old-fashion WCAT. Ed Glas from adCenter team posted a blog entry saying they have tested 100+ servers.
Test duration: 12 hours
Total requests generated: 3.63 Billion
Avg requests/sec: 84 248
Avg agent CPU utilization: 45% (sounds as a good load)
And this is done with Visual Studio Team System.
(Read Ed's full blog post)