It seems like the core of Docker is little more than a helper script that should be part of libvirt or LXC proper (which btw, already has a system for building containers from a template), but that would involve less horn-blowing and web design than it would submitting boring, well-tested old patches upstream.
DotCloud have done a wonderful job of popularizing the idea of LXC containers with Docker. I think the idea of LXC containers as software-distribution mechanism is a great one, and I credit Docker with getting that idea into my mind.
It is great to see that many of Docker's ideas are being implemented upstream; e.g. LXC added support for BtrFS snapshots shortly after Docker launched. Sounds like OpenShift is considering which Docker ideas belong in their platform.
It can sometimes be hard to work with upstream projects, who often have a different world-view. I do like the idea of releasing a "sacrificial lamb" project that is a demonstration of your ideas, even if long-term all the ideas belong upstream (i.e. LXC in the case of Docker).
I think jQuery is a good analogy. One day jquery might be unnecessary, when all browsers everywhere implement all the high-level API goodness. In the meantime... :)
