[ekiru]

Regardless of whether or not Thesis and other WP themes are actually legally required by the GPL to be distributed only under the GPL, if one believes at all in the concept of copyright, it's ethically, if not necessarily legally, important to consider the intentions of the developers of WP in using the GPL.

It's clearly the case that both Wordpress and the FSF believe that programs which link or include GPL-ed works are derivative works. Even if they're wrong, isn't it somewhat unethical to agree to an agreement and then violate what the other side of that agreement have told you from the beginning they believed it means?