The way I always looked at this issue was like this: Someone gives you a copy of (say) xsoldier, under the GPL v2, or later, *your choice*. You can choose to pass that extra choice along to everyone you distribute to (I like doing this) or you can choose not to.
The choice itself is not a part of the GPL if I remember correctly. It's like Perl - you can distribute it under the artistic license, the gpl, or both. Right? -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]