The Nehalems will be made on a 45nm process, the chip will use a new socket but the form factor and pin count hasn't been determined yet.
The consumer chips will use standard DDR3 memory and the memory controller will be integrated in the Nehalem's die. For servers the chip will support both FB-DIMM and DDR3 memory modules.
Some other details:
The interconnect between other processors in an MP system will be a serial derivative of PCI-Express, as will the interconnect to the I/O Hub. No details are available as yet as to whether the next generation I/O Hubs will be single chip or a northbridge-southbridge chipset solution, although nothing is ruled out. The integrated graphics will be DirectX 10 and offer GPGPU functions if the software used is able to address it -- Intel is currently working to make the software available. Intel is basing the graphics core on a derivative of Intel Architecture (IA) that it uses on its CPUs since the general purpose processing now done on a unified shader GPU core is very similar to that of a CPU. Intel says it’s capable of not only DX10 but OpenGL and GPGPU as well, although performance information isn’t yet available, but expect it to be still quite basic compared to a discrete solution.