WTF is Alpine Linux? You probably don't know that there is somewhere in the Distrowatch pages, laying around a tiny-mini Linux that just run perfect with ultimate hardened security, like Alpine Linux.
So, later this year, Docker Official Images will be moving to Alpine Linux from Ubuntu base Images. This rumours started on Hacker News mailing list
https://news.ycombinator.com/item?id=10998667 debating about CoreOS that later reveal that the creator of Alpine Linux,
Nathanel Copa is now working at Docker,Inc.

IMHO, Docker is begin to follow the CoreOS direction by moving their product to running in small and compact environment. CoreOS is using their own customized version of Gentoo as their bases.
Is it Good?
Just downloading the Ubuntu official image from Docker Hub is 188MB and it has been downloaded over 40 Million times which equates to over 7,520 TB of data transfer between Docker Hub and users around the world just for this single image. Multiply this by all the official images and the amount of transfer data is mind boggling.
So how will Alpine Linux benefit Docker Official Images?
- Speed in which the image is downloaded, installed and running on your Docker host
- Security is improved as the image has a smaller footprint thus making the attack surface also smaller
- Faster migration between hosts which is especially helpful in HA/DR configurations.
- Your system admin won't complain as much as you will use less disk space
Do you interested to help Docker to moving to Alpine Linux? Solomon indicated in his HN comment that Pull Requests on the Docker Library is the best place to start.
What are you waiting for? Make the Docker world a better place and start converting this images now.