This is interesting. Do you have profiling information about Rails vs. Django in general and Django on PyPy in particular? It would be very curious to look at it from a performance point of view.
My opinion is base on the following benchmarks : http://attractivechaos.github.com/plb/. This is obviously not a typical web application, but it gives a good hint on the performance issue.
Those interested in a C++ web app framework might consider wt (webtoolkit). It has a built in http/https web server and is thus plug&play for average applications. It is worth a look at.
