You might explore the use of Symbols and the Update command within the Document Library fly-out menu. According to the following Adobe Help page, “Imported symbols maintain their link to their original symbol document. You can edit the original symbol document and then update the target documents to reflect the edits.”
Otherwise, have a look at the Linked Images panel extension created by John Dunning: http://johndunning.com/fireworks/about/LinkedImages
Thanks for the reply. Here's a quick exerpt from John Dunning regarding his LinkedImages extension that seems to address this functionality!:
When you import an image into a Fireworks document, Fireworks doesn't maintain any link between the source file and the bitmap element in the document. If the source file changes, you'll need to find it, re-import it and then delete the previous image in the document. The Linked Images extension makes this process a little easier.
I'll further test this solution and let you know how it goes. Also, I tried the solution you presented using Symbols, but could not get the image to come across correctly.
Again, thanks for the insight!