When opening the dash with my super key and then deciding that I do not need the dash after all, I can dismiss it either by pressing the super key again or by hitting escape. The first thing that comes to my mind though is to click outside of the dash, but that does not do enything. Is that intended behaviour?
UPDATE: this has been spurred by this bug: https://bugs.launchpad.net/ubuntu/+source/unity/+bug/798642