I'm a developer on the Xbox Live SDK team.

We recently announced the Xbox Live Creators Program which allows all developers to use Xbox Live via no concept approval required! More info can be found here: http://www.xbox.com/en-US/developers/creators-program

We also put the source of the Xbox Live SDK on GitHub. The various projects can be found at: https://github.com/Microsoft/xbox-live-api

https://github.com/Microsoft/xbox-live-samples

https://github.com/Microsoft/xbox-live-unity-plugin

https://github.com/Microsoft/xbox-live-trace-analyzer

https://github.com/Microsoft/xbox-live-resiliency-fiddler-plugin