A few weeks ago, a District Court in Munich, Germany, upheld an earlier preliminarly injunction according to which the GPL can effectively become part of an agreement und that it may be enforced by German courts. While this story has been reported occasionally, if you want to have a look at the actual decision, here is an (unofficial) English translation.
Update: Some more information (a different English translation and a commentary by Prof. Thomas Hoeren) may be found via Larry Lessig's blog.