When we move downward on the block diagram we notice that the MCP is missing a couple PCIe lanes. And hey, not needed as you'll have two PCIe x16 slots, not three and thus plenty of PCIe lanes available. NVIDIA however did want to make your system PCIe 2.0 compliant, so they have inserted a bridge chip called the NV nForce 200 that is responsible for creating 2x x16 PCIe lanes fully compliant with the 2.0 standard.
The new PCie 2.0 standard, brings a boosts to the PCIe interface. The total capacity of the PCI Express 2.0 bus is now 5Gbps, twice the old standard, and an x16 connector will now be able to achieve transfers as high as 16Gbps. It is backwards compatible with PCIe 1.1 cards, making it simple for motherboard manufacturers to transition to it in the future. Cool stuff, yet it's so high-end that at this time you will just not notice a performance difference. The latest G92 graphics cards already have 2.0 compatibility though.