Docker keeps fascinating me, purely as a use case. From the image hosting perspective, there are a couple things that are missing in its current stage of development. The biggest and the most obvious one is – a shared, distributed, and deduplicated store for both image manifests (image metadata) and layer content (the data).
Due to the immutable sha256-protected nature of both the related complexity is about 3 orders of magnitude lower than (this complexity would look like for) anything less specialized.
Distributing the content-hashed and stacked stuff like this: