The in-content preferences being implemented as bug 718011 will use instant apply on all platforms. We should provide a way for users to revert or reset their preferences for some predetermined time after they have made a change. From Benedikt P. [:Mic] at http://msujaws.wordpress.com/2012/02/14/msu-cse-capstone-update-214/comment-page-1/#comment-1464: > Will there be a way to restore previous settings or to undo a change (e.g. if > someone accidently selected a different font size from the dropdown and has no > idea what it was before)? I really liked that I had to explicitely accept > changes until now or could discard them if unsure. You just couldn’t do > anything wrong unless you clicked the OK button of that dialog.