It looks like nForce will be the name of the project that will bring PCI Express to the Athlon K8. This new chipset will be socket 754/939 ready and 940 compatible. All Athlon 64s, FXs and Opterons will work with it. Boasting one to two PCI Express 16 slots (Geforce SLI anyone??), nForce 4 is also equiped with Sound Storm 2 and a host of other features.
More here.