The docker ps did also hang for me after the upgrade. It wasn’t enough to restart the app or toggle the VPN mode, though. I tried re-installing with a fresh download from beta.docker.com, which also didn’t help. Only a complete system reboot made it work for me.
OS X: 10.11.4 (15E65)
Docker: Version 1.11.0-beta8 (build: 6072) 3c1bfeb0e86a9403f82302edfea4c4987cc2cb32