It is codenamed RD600 and this one will have no less than three PCIe 16X ports. As you might know, ATI wants to do a lot with what the chip firms now call physics. Most especially it wants to get you buying three graphics cards for your PC.
Two cards for graphics will cost you and a third one for physics might not be super expensive but it won't be cheap either. Of course, it all depends on what you want, as the top ATI physics chippery comes with the top ATI graphic card.
That's why you'll need a third PCIe slot.
The RD600 chipset will support Conroe, Intel Core 2 Duo CPUs and it is expected in the next few months - probably before the beginning of Q4 2006.
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.
For the time being, Intel 975 and P965 are the only good Conroe chipsets although Nvidia might have its C19+C51 Northbridge chipset at the launch to support Conroe as well. µ