To get an idea as to what sort of image tagging is currently being used, I did a survey of the license tags applied to the 2000 most recent images uploaded (which represents about 24 hours and 20 minutes of uploading). Of those images, 134 were duplicate uploads or otherwise not accounted for, leaving 1,866 images to check for tags. The detailed results are at http://en.wikipedia.org/wiki/User:Carnildo/upload_stats
For 1,866 images uploaded, 2,014 license tags were applied:
745 images were tagged as some sort of "fair use". The vast majority used one of the boilerplate templates, with most of the images being tagged as screenshots, covers, logos, and promotional images. Only 26 generic "fair use" tags were used, with most of them being "fair use in".
412 images were tagged with a "public domain" or equivalent tag, with most of these being PD-self and "No rights reserved"
368 images were tagged with a free license tag. 275 of these were GFDL, 77 were Creative Commons, and the rest were an assortment of other free licenses.
176 images were tagged with a license template that doesn't indicate the license status, such as "don't know", "no source", or "no license"
313 images had no license tag at all. This includes images that were deleted before I could check for a license tag, so the number may be misleading.
The "CopyrightedFreeUseProvidedThat" tag is a problem: of the seven images so tagged, two of them had decidedly non-free "provided that" clauses, forbidding modification and commercial use.
-- Mark [[User:Carnildo]]