It appears that Microsoft is pushing for Windows 10 support of Thunderbolt. They have released info for developers to set up drivers which would access the PCI Express bus.
why is everyone so excited about Thunderbolt? it is really just another PCIe connection. i worked the NAMM show for Ferrofish. Ferrofish is distributed by the same folks who distribute RME. RME doesn't even have a Thunderbolt interface and the reason is that USB2.0 works better than Thunderbolt. this info came from the tech who writes driver code, not just salesmen. there's always a disconnect between specifications and real world performance.
I have never seen, nor do I ever expect to see a Cardbus slot on any of these thin and light touch laptops like my beloved Lenovo Yoga 2 Pro, but I can totally foresee a near-future version or similar device with a Thunderbolt port.