ATI is expected to ship its RS485 and RS490 chipsets shortly, if it hasn't begun to do so already. The RS485 is said to be a tweaked version of the already-shipping RS482. Both parts incorporate a Radeon X300 graphics core, but the RS485's is clocked higher than the RS482's. The RS485 is said to be pin-compatible with the RS482, ensuring a relatively smooth upgrade path for motherboard makers.ATI is also preparing the RD580 chipset, which will feature dual PCI Express x16 CrossFire support.
Source: The Register.