Comment 3 for bug 900191

Trunk has a fix for this now, pressing left or right Super reveals the launcher. Opening Dash requires pressing Super+Tab.
With Super alone, opening the launcher (and not Dash) is the best I can do at the moment. In order to open Dash, Unity apparently checks for a very short duration between super key press and release. I haven't found a way to achieve that duration without disabling the sticky key feature and we need sticky keys to allow for entering Super key combinations.