PCI-Express 2.0 has been here for us for what seems like an eternity in the tech world - so much moving past us in terms of cores on a CPU, the amount of system ram and at the moment the apocolyptic GPU wars between the great AMD and NVIDIA.
PCI-Express 3.0 is the next gen champion to be on your motherboard. It is rumored to be clashing it's hammer with the Sandy Bridge E 'Patsburg' on LGA2011 which is slated for 2011. Depending on whether the LGA2011 becomes the consumer-targetted replacement. The closest definite for PCI-Express 3.0 is for early 2012 when Ivy Bridge hits.
Source :
PCI-Express 3.0 - nearly finished being an unsolved mystery :: TweakTown USA Edition