Ævar Arnfjörð Bjarmason wrote:
Trademark protection is necessary to prevent forks or other encyclopedia projects from claiming to be the real Wikipedia.
The issue is not trademark protection, it's copyright protection. Wikimedia claims copyright over the images and won't license them under a free license, I don't think anyone would have an issue with them still protecting it as a trademark if they would do so.
They received legal advice that the trademark might be difficult to defend in court if they had granted a license which conflicts with the common law restrictions placed on use of trademarks. The GFDL is such a license, it explicitly specifies that one may use the licensed content in any way, making no exception for use of an image in identifying an unaffiliated product.
In other words, someone may well have an issue with them still protecting it as a trademark, specifically the courts and the trademark infringer.
My idea for dealing with this situation is described at http://tinyurl.com/85cae#Suggestion .
-- Tim Starling