In [[https://www.mediawiki.org/wiki/Usability_testing_citations_dialogue_on_VE,_brand_new_editors_%28May_2015%29|usability testing conducted on 12–13 May 2015]], only 6 out of 10 news users were able to successfully save their edits—the lowest rate among all the tested tasks.
This is likely due to new users being familiar with online WYSIWYG editors like Google Docs, which automatically commit changes as they're typed, without any discrete save step.
Drawing their attention to the save button would help address this; one way to do this is to stick the progress bar directly to the bottom of the VE toolbar, so that as it completes it "pushes" towards the save button. This would require creating as "ghost" version of the toolbar as soon as VE starts to load: we draw the progress bar in the middle of the page rather than just below the toolbar because users can scroll down, away from the toolbar, even while the page is loading.