Where are the external PCI-e enclosures, or docking devices that actually have a decent set of ports?
As the thread's initial article points out they are largely waiting on software to catch up.
Part of the myth about Thunderbolt was that no new software would be needed. That's isn't true even though can probably leverage much of exististing PCI-e driver code base. The huge problem is much of the PCI-e driver software was not written or enabled for hot-plug environments. The device was always going to be connected so the driver software creators made lots of implicit assumptions. That typically fails once the device can be decoupled. Likewise as in articles case where the PCIe device is on a separate power supply with separate power management.
USB 3.0 has very similar issues. Without newer xHCI driver oriented softwware, new USB 3.0 connector-cable , and improved protocols ( SCSI over USB UAS & USAP ) most of the new benefits of USB 3.0 don't appear.
Note that vendors who have control over both the software and hardware stack ( e.g., higher end PCI-e card vendors in the pro capture space) did manage to get products out quicker.
The vendors who depend upon the OS vendors to provide core services will trail behind. In part because the system stack is spread over several organizations with different R&D timelines.