It would be nice to be able to replace an image which is already in the document rather than having to delete it and then add in a new one. Why this would be even more useful is that the same options already set on the image that is to be replaced can be kept, likely with an checkbox in the file open dialog.
A cann of worms Jay :) See bug 55582 (and many more?) If you are brave enough: pls start and _guide_ a proper, well attended discussion with enough input from all stakeholders on UX or so ;) Sorry for not making this easier..
*** This bug has been marked as a duplicate of bug 36486 ***