yourbankruptcy, AGP problem
While you shouldn´t take my word for it (and I mean that), I know for a fact that there is no such problem. The reason for the delay is that Athlon64 can´t reach the necessary (to be competitive) frequencies on the current design, which is why a redesign to optimize the speed paths is in the works, with the help of IBM.
As for bad 3d performance on CeBIT demo systems, well, you can guess why that is.