We'd love to have ASP.Net MVC included. One minor gotcha is that to do it justice, we'd need to spin up a Windows EC2 instance and figure out how to script that. It's on our to-do list!
We did briefly test ASP.Net on Mono (see another comment in this thread) but didn't include it since we didn't believe that qualifies as a "production" grade ASP.Net MVC deployment.
Since these benchmarks are so wide-ranging, I agree. But that means setting up an entire new testbed on Windows, and then trying to make it comparable to the other platform testbed; possibly tuning. You need a Windows expert to do this. My question is, why aren't Windows experts setting these up?
If you can cover ASP.Net MVC, then I'd recommend including ServiceStack. My own tests of their JSON implementation have shown it to be 5-10x faster than ASP.net MVC.
(The big four in my book are: ASP.Net MVC, Rails, Django and CakePHP)