The BR2 chip used for NVIDIA's NV43 can bridge native PCI Express back to AGP, and that's exactly what NVIDIA is planning to do for their GeForce 6600.
Nvidia has to build new PCB to be able to fit both NV43 chip and BR2 bridge chip on the same card and that’s why this card will be introduced a bit later than the native PCI Express cards that are expected in just a few days.
I guess this PCB won't have an SLI connector since you can't use two AGP cards inthe same machine so it would be just a waste of wires on a printed circuit board. But as always what ever costs less to produce my silly old champ.
We are told to expect this card in November and we expect the same clock speeds for AGP and PCI Express cards.
It would be interesting to see what ATI is going to do about this AGP card as its X700 card is PCI Express and it doesn’t have a PCIe to AGP bridge, yet