[citation][nom]Pinhedd[/nom]Seems reasonable enough to me. I don't see why Intel should complicate things for motherboard manufacturers by using a 2000+ pin socket when they don't have to.[/citation]I agree with this. Pin compatibility between generations of CPUs doesn't make much sense, because virtually nobody upgrades from one CPU generation to the very next. By the time you do upgrade, there are new memory speeds & bus standards (USB3, SATA3, PCIe 3.0) that most enthusiasts will want to utilize. And besides enthusiasts, who else would even consider upgrading just their CPU? Not many, for sure.
And within a generation, one of the things that differentiates between markets (i.e. big server vs. small server/workstation vs. desktop) is # of PCIe lanes, memory channels, and multi-CPU support. All of those affect the socket, since the DDR and PCIe controllers have been moved on-die.