Hardware Secrets posted an article on the Nehalem Microarchitecture

Nehalem is the codename of the new Intel CPU with integrated memory controller that will reach the market next month and that will be called Core i7; this architecture will also be used on CPUs targeted to servers (Xeon) and, a few years from now, it will also be used on entry-level CPUs. CPUs based on this architecture will have an embedded memory controller supporting three DDR3 channels, three cache levels, the return of HyperThreading technology, a new external bus called QuickPath and more. In this tutorial we will explain what's new on this architecture.

Inside Nehalem Microarchitecture