upgrade with new boot2docker image (docker 1.3)

I just removed guest addition (already done in the new b2d image, v4.3.18) and change version number.

The main question remain about security, the b2d image start docker using tcp://2376.
It's a bit frustrating. Using 
export DOCKER_OPTS="-H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375"
in /var/lib/boot2docker/profile does the trick but maybe it should be integrated in the box ?

Regards

Pouic