I'd be interested in a link to that benchmark if you have it.
I assumed that you're talking about http://ziutek.github.com/web_bench/, but that makes no mention of PyPy (other than a HN comment that PyPy takes 2x the memory) and Go comes out on top in that benchmark.
Either way, when saying Go is faster, I wasn't talking specifically about it's http library or io system (I assume both are similar in speed to Pythons). I more meant that if you're going to be writing custom CPU-intensive code to run on App Engine, assuming the same algorithm, Go should be faster. It has better constant factors, and it gives you better control over allocation.
I don't know PyPy well enough to say in what situations it outperforms Go (especially considering that I don't know what kind of VM warm-up you can expect on App Engine), but since GAE doesn't run PyPy, it's not relevant to the discussion of Python v Go on App Engine.
