Is Thunderbolt 2.0 capable of PCIE 3.0 16x external enclosures? I mean can you have an external bay with one PCIE 3.0 16x graphics card in it? What bout two? I reckon that the GB/Sec. of Thunderbolt 2.0 certainly indicates it's capable of this, and it's touted as PCIE 3.0 tech. We've already seen there are currently PCIE 2.0 16x capable enclosures on Thunderbolt 1.0, although the performance is maybe 10% less than a real slot (I think?) due to extra lag from the Thunderbolt controllers and signal propagating down a 3-foot cable etc. I kind of doubt Apple would introduce a mac pro that CAN'T have PCIE 2.0 16x slots added. Am I wrong? Not that you'll likely need extra graphics card power beyond what appears to be DUAL AMD FirePro W9000's, which currently run about $3000 APIECE... but hey. Just curious!