New guid? Good for those guys who have quite a lot bans on their old one, I guess. PBBans and stuff. Will check mine, too. Have 2 keys with quite some bans.
EDIT: Nope, no new guid for me either.
I don't think they are talking about PB GUIDs. There are 2 GUIDs for COD2 version 3 - one is the game GUID generated from your CD key; the other is your PB GUID generated from your game GUID + a PB algorithm. But versions 1 - 2 only have a game GUID that works.