Jacqueline D. Lipton and John Tehranian have published "Derivative Works 2.0: Reconsidering Transformative Use in the Age of Crowdsourced Creation" in the Northwestern University Law Review.
Here's an excerpt:
As such, this Article reflects on the particular problems raised by the growth of crowdsourced projects and how our copyright regime can best address them. We conclude that future legal developments will require a thoughtful and sophisticated balance to facilitate free speech, artistic expression, and commercial profit. To this end, we suggest a number of options for legal reform, including: (1) reworking the strict liability basis of copyright infringement for noncommercial works, (2) tempering damages awards for noncommercial or innocent infringement, (3) creating an "intermediate liability" regime that gives courts a middle ground between infringement and fair use, (4) developing clearer ex ante guidelines for fair use, and (5) reworking the statutory definition of "derivative work" to exclude noncommercial remixing activities.