DDR_SDRAM chipset support from Intel is due Q1 2001 for the P4, while SDRAM support is due late Q3/early Q4.
When the 'Northwood' P4 comes out it will be on mPGA Socket478 rather then the current 423pin socket of today's P4. It will be introduced with 512KB L2 cache on a 0.13 micron process, and I believe though I'm not sure that it is supposed to debute at 2GHz.