Lies!
PCIe is integrated into the processor. The current chips of the 2xxx series only support PCIe2. You will either need a Sandy Bridge-E series processor (which is crazy expensive), or wait for the Ivy Bridge processors which will be released late Q1 or early Q2 of 2012.
There are motherboards which will 'support' PCIe3, but as the PCIe lanes are on the processor it just means that they will later take an Ivy bridge processor, and allow the PCIe3 bus to pass through. How true the advertizements are on PCIe3 support is cannot be tested until next year.
Besides, there are no PCIe3 GPUs out yet, so if you are building now, you will need to buy a processor next year, as well as a PCIe3 GPU next year. Not to mention there will likely be better chipsets out next year with the new processor release, so if PCIe3 is of major concern for you, then just wait till next year