Actually both NVidia and MS have announced that the XBox will use AMD's LDT (Lighting Data Transport/Hypertransport).
As for that article, it seemed to be regurgitating much of what is already known. And the lack of an AGP bus doesnt inherently make a console faster than a PC. If that was true then an old Super Nintendo should be beating our PC's, while the PS2 and the like should be far better. I don't put much faith in how accurate the article is, especially since the XBox has yet to be released so no one knows how it will really perform.