I nearly always zoom in and out using ctrl- / ctrl+, but often want to see my comp in the 'fit to view' magnification. It'd be nice if this was one of the 'stops' when zooming like this. I know it breaks the convention that each level of zoom is half/double the previous one, and it possibly might very slightly confuse someone in the rare situation if their window layout happened to mean that the 'fit' view is, say 52.3% (then zooming in from 50% would have a negligible effect), but I do think it'd be useful.
Good idea, don't you think? Upvote! Upvote now!