It is worth pointing out Go 1.0.3 not Go 1.1 beta is being used. I tested the code locally and on my machine 1.1 beta was about 20% "faster" (req/sec).
In addition to the improvements from the improved scheduler, use of accept4 on Linux, better GC and code generation, Brad Fitzpatrick has been giving a lot of love to the "net/http" package. Here is a small example: https://plus.google.com/u/0/115863474911002159675/posts/L3o9...