Intel is informing its partners that it wants to stick to Core 2 Duo and Quad generation all the way to 2011. It expects that the 4 series of chipset based platforms will stick around for mainstream and value all the way to 2011.
To ensure that these chipsets will stay future proof, Intel wants to refresh these chipsets, mostly with DDR3 support and some other media enhancements.
Since P45 and P43 were mostly DDR2 1066 supporting chipsets these two will get DDR3 1066 support. G45 will also get DDR3 and some media enhancements and most important it will be ready for Windows 7 transition.
Despite Core i7's performance dominance, Core 2 generation still offers much more for the money and this will remain the case at least through 2009 and probably beyond.