I wrote a tool to integrate GitHub pull requests with Jenkins builds called Leeroy: https://github.com/litl/leeroy
This new feature will make things so much easier to set up and debug, I'm thrilled. Before, you could not create a pull request hook without using the API, and this caused a lot of people confusion. We set up the hook automatically in Leeroy, but this will allow people to set it up manually if they want, and debug when it doesn't work.