As a sample though in '05. Well the G4 chips have dried up. The only G4's we know about that are faster then the 7447A is all prototypes and won't be shipped intill mid next year. Ok, back on track the 7448 is single core. The MPX bus is still external. IMO, the G5 pbook chances of coming in January just went higher.
http://www.eetuk.com/tech/news/showArticle.jhtml?articleID=47903043
http://www.eetuk.com/tech/news/showArticle.jhtml?articleID=47903043