I've been hearing about LXC and Docker (hereafter "Docker") from all around the internet over the past few months. If you pay attention to Linux developments at all, you have probably heart about them both.
A while ago I outlined a solution to fix the internet, which would shift control of the internet to individuals and away from centralization.
Docker makes this project much easier. Installing and running many pieces of software on a system can cause them to interact in problematic ways. Beyond that, the entire system is made more complicated by each new component that is installed.
Instead of having configuration, logs, data, and binaries all on the same system, Docker lets us contain each application in its own machine. That way, each container much easier to understand, debug, and can be consider independent of the rest of the system. Before Docker, we could have simplified the project in the same way by installing each piece of software on a separate machine. Realistically, this would cost way too much.
I am pumped. In my mind, Docker removes the majority of the work blocking us from having such a system today.