Intel Core i7 is the successor of the Intel Core 2 processor. It was released on 17 November 2008. The i7 will move from the previous Core microarchitecture to the Intel Nehalem. This substantial change in Intel's architecture will allow a multitude of technology upgrades.
Some features of the Nehalem include mandatory use of DDR3 SDRAM, support for 2, 4 or 8 cores (i7 will have 4), ability for the cores to clock themselves using Turbo Boost tehnology (only when user is not overclocking) and advanced power management with the ability to make an unused core use no power at all. A motherboard that supports QuickPath (providing high speed links to shared memory) is needed to support i7, the Intel X58 and MSI X58 both support QuickPath. The memory controller will be directly connected to the CPU instead of a separate chip to improve performance.
The CPU clock speeds in the Intel Core i7 will range from 2.66 to 3.2GHz. However, with overclocking the clock speed can reach potential of over 4GHz. It will have 8MB of Intel Smart Cache and 3 channels of DDR3 1066 MHz memory. Users will be able to view 8 cores on their operating system although the i7 only has 4. This is because every core will be able to process 2 threads at once and 4 cores x 2 threads = 8 visible cores.
It would also be wise to keep in mind any i7 builds in the near future are going to be considerably more expensive in comparison to a top of the range Intel Core 2 setup. Unless you have atleast a thousand dollars extra to blow, stay away from any i7 build for a while.