Hi,
I think a project aimed at improving image management in Inkscape would be great for students fromEcole Centrale Lyon. If you think it's a good idea, I could mentor a team of students that could work on this. (The same kind of work than we've done in the past : LPE for groups, stacking and envelope 2 years ago and Spray tool last year).

Concerning the smart broken link feature:
Gez was worried about the time image path replacement would take. But in fact, once the system has found the new paths, it is only a replacement of XML attrributes. I think it doesn't cost computation time at all. Gez mentioned computation time needed when ungrouping a large group of objects, I think this is due to big XML manipulation. Here it's only an attribute replacement. But I may be mistaken, someone can help us ?

I still want to discuss about the ID field. I don't think it is a good idea to put it in "Image Properties". For me the user identify the image by either a thumbnail or the path.
The ID field is already accessible in the "Object Properties" window. The user case Gez mentioned that uses ID is web design (we can consider that for artistic work, keeping all IDs meaningful is too much work). I think the "Object Properties" window is sufficent and may be more the window to open when doing web design.
So I would vote to remove ID from the top of Image properties. We can remove it completely or move it to "show image details"

A last point to discuss is an Image manager. I described it in my initial blueprint: http://wiki.inkscape.org/wiki/index.php/Image_links_manager
I think the enhancement of the image properties window is great. And I wonder if an other window that regroups all the images currently in the document can be useful. This is to discuss.

Steren.