Except that these things are already happening, even with USB2. Firewire was too niche and too expensive, Thunderbolt is too Apple (read: too niche and too expensive), USB3.0 is now becoming everywhere and the devices are appearing (check SDR boards for an example, though it is still mostly the domain of mass-storage devices), PCI and PCIe are a domain of special and expensive data acquisition cards and never could do much beyond that because of a host of reasons dealing with the form factor, the connection right to the bus, and the related design/construction needs; good for a lab, poor for the field.
There is a reason to hope it will be different this time, because the other variables the results depend on are changing.
