FUD Zilla claims AMD has delayed the RD890 and SB850 chipsets from late Q2 2009 to Q4 2009. These chipsets will replace the 790FX and SB750.
The chipset is AM3 only, and AMD wants to get rid of AM2+ legacy and infrastructure and continue with DDR3 platform. The new RD890 chipset supports HT3, 2x16PCIe or 4x8 with second generation PCIe , as well as enhanced Quad Crossfire X 4x8 support.
The SB850 Southbridge has all the features of SB750 Southbridge as well as Gigabit MAC, AHCI 1.2, new clock gen as well as second generation PCIe 4X.