Basically, I am happy enough with the upload wizard, and limiting the functionality to Commons-enabled licenses would be good enough for most of the use cases of casual image contributors. Yes, the assessment needs to be done by community specialist, but I think that is actually better separated than trying to limit the image contributions to those who understand enough about Creative Commons, Fair Use, etc.
I would love to see page context (across page-wiki and commons-repo-wiki) and something like adding the images to a "new-media-section" on the page-wiki being added. License assessment, image selection, better image inclusion all being decoupled from image contribution.
Neil, Erik: do you see a chance to put this into a wmf working plan?
Gregor
PS: I tried to test the AddMediaWizard on both 1.18 and 1.19 trunk. Is my analysis correct, that it cannot possible work? It requires enabling require_once( "$IP/extensions/JS2Support/JS2Support.php" ); which no longer seems to exist in wmf mediawiki subversion. If this is true, I think AddMediaWizard should also be removed from versions with which it no longer works as well.