Looks like Conroe's going to be the first beneficiary of ATi's physics-on-a-card technology. The Inq is reporting that ATi's RD600 chipset for Conroe will support the necessary third PCIe x16 slot.

"It is an Intel-only chipset and there are no signs of an equivalent PCIe 16x3 chipset for AMD. ATI wants to focus on Intel and wants to be early on the Conroe bandwagon so it can make some extra money."