(newbie alert! sorry if these are repeats; I did read tons of the existing suggestions...)
Would be nice if the mouse-over object moved with the object. I had an html object which overlapped a button (with mouse-over); moved the button way out of the way and still received an error. Had to delete the button and try again.
Ability to select objects with keyboard or some menu. For example, say you want to select some object which is behind another. Maybe Tab/ Shift Tab to select next/previous object? Would be great for the previous suggestion (select the mouse-over object so you can move/re-size it).
Ability to copy/insert a page from another website.
Ability to have multi-language pages. Kind of hard one; you would be able to have text in a text box pulled from another file, depending on a variable which could be set via a button.
Spell checker
(how many times have you heard that one?)