Glad I'm not the only one. I maintain an embedded system and a bunch of its apps - at every point in the Docker file where mknod & friends must do their thing, I have to cut the Dockerfile right there and do docker run --privileged for that build step... and so on.
It hasn't bothered me enough to comment on that issue though, Docker has really improved my workflow enormously.
https://github.com/docker/docker/issues/1916
That said, yes this release looks interesting!