We've been hearing a lot about the new Core i5/i7 CPU's, and generally we like to reserve our opinion until the test results are in. We've benched the Core i5 750 and Core i7 870 extensively. We've added a bevvy of tests to our benchmarking routine and Core i5/i7 LGA 1156 is looking pretty good.
The P55 chipset is not based on the traditional 3 chip (NB/SB/CPU) design and the NB and SB have been replaced with the PCH or Platform Controller Hub. The new design moves a lot of the PCI-E lanes on to the CPU Die and the rest are handled by the PCH. Most of the traditional NB/SB functions are handled by the CPU/PCH on the new P55 platform. As time progresses you can expect to see more and more functions moved onto the CPU die itself.
While many are resistant to change and have the 'it was working why did they fix it' attitude they need to realize this is going to be a vital evolution in computing. It might seem like a small change on the surface but with on DIE PCI-E and moving to a 2 chip solution you reduce latencies, you also reduce the amount of coordination between chips. Instead of the CPU handling the communication between NB and SB and trying to make sense of signals coming from two different directions it either handles the I/O itself or the PCH feeds it the information.