The Old Way
Intel has been doing things the same way for a long time. Anytime the CPU had to talk to something, it got on the Front Side Bus over to the northbridge, which could be thought of as a roundabout (ed.- traffic circle) with exits leading to the memory, PCI-E cards, and, via Direct Media Interface (DMI), the southbridge (a roundabout in its own right; with exits for hard drives, USBs, etc). Chipsets with North and South Bridges are explained here.
This lead to two big problems. For one the FSB only goes in one direction at once. If the CPU asks for something from memory, once it starts coming back, the CPU can’t say "hold on I want something else" or wait I need to tell the graphics card something" until the memory has said its piece.
The other issue is that the PCI-E, memory, and southbridge data all waiting to pull into the roundabout create traffic jams, or, returning to computing parlance, bottlenecks.
Also, the new Core i7 chips run on the LGA1336 sockets. Usually a new socket is a pretty big deal, but it actually is over shadowed by the other new features in the X58 chipset.