Again, I ask you: when Section 6 says "these terms and conditions", to which terms and conditions is it referring? I don't honestly see how it could be referring to any terms and conditions besides those of version 2 of the GPL. Now re-think your answer in light of this information, and have your lawyers friends do the same.
\r\n\r\nAnd if you could point me to a publicly archived mailing list where this has been asked, and answered by a licensed attorney who practices in the field of copyright law (even better if they routinely work with GPL issues), then I just might be more inclined to believe you.
\r\n\r\nAnd as for the "don't you think they'd have come up with it already" argument, I do wonder whether anyone ever sat down and thought out what would happen if a future version of the GPL wasn't compatible with previous versions; as I read it (and, dear Ben, I used to literally do IP research for a living, as that was what got me my grant money in school, so I'd like to think I can read a license and get the salient points), the GPL is rather optimistically written with the assumption that future versions will remain compatible.