I think there should be an option to toggle the mega menu or dropdown with onclick. Currently the default is hover but with the trend of touch screens an devices coming on board (Microsoft surfaces, hp/lenovo notebooks) I think this should be considered. Maybe in the these options service this as an on/off button in the header settings.
Speaking of, do you know where in the theme files I can hack this to work with onclick vs hover and for the menu to close with the mouse scrolling off the menu?