These chipsets will replace the current P35 and G35 chipsets in the second quarter of 2008.
As it is a new chipset, it will support the PCIe 2.0, south bridge will also be using a newer ICH10 or ICH10R. The chipset will maintain the suppot of DDR2 and DDR3 memory type.Source: OCWorkbench
Eaglelake chipset will be known as P45 (discrete) and G45 (for integrated video with GMA x4500 with DX10 support).
The chipset supports new standards like display port in additional to the DVI, HDMI. It will also have hardware acceleration for HDDVD/BluRay. The chipset is said to officially support FSB1600 processors.