Petar Maymounkov introduces Go Circuit, a system that reduces the human development and sustenance costs of complex massively-scaled systems nearly to the level of their single-process counterparts.
Rob Pike explains how Google designed Go to address major development issues they encounter while using other languages: long build times, poor dependency management, lack of robustness, etc.
Andrew Gerrand introduces Go, demoing some of its main features through examples: a concurrent echo server, chat, channels, error handling, etc.
Brian Ketelsen introduces Skynet, a platform for polyglot, distributed and composable services that communicate with each other over RPC/JSON.
Bruce Eckel emphasizes using different languages within a project, each one for the task it is better fitted for, and giving several such examples: Python+Scala, Go+Python, Python+CoffeeScript.