A possibly bad thing I see about this, there seems to be a segmentation of sorts. I've noticed there are now a few conflicting editions of Docker Engine. There's CE and EE now, then there's some version that Docker Cloud Agent bundles, and probably more. (Maybe I'm wrong, though)

Maybe that's just me, but it would be better if there'd be one core to rule them all, and extras would be managed by plugins/wrappers/companion daemons. So if you have Docker Engine installed you're good to go.