Rename to MediaWiki (name of the software; WikiMedia is a Foundation, Commons a specific project)
Allow image resizing by a percentage of the initial size
Add explicit error messages (might require hacking libmediawiki)
Check for local duplicate file names (easy)
Check for distant duplicate file names (API)
Check for distant duplicate files (API)
Write a documentation
Pre-fill the description in several languages
Color the categories depending on their existence on the distant wiki (AJAX, API)
Apply a tag on uploaded images (eg. "Now on Commons")
Allow editing and deleting wikis
Allow editing and deleting licenses
Add a notification zone to tell about problems or if everything is ready
