3.0 has been a LONG time coming. 2.0 came out in 2000. That’s almost 10 years since the last revision of the interface.
I would say it’s about the right time for this, and there will be plenty of cheap USB 3.0 cards coming soon. PCI-Express needs to completely replace PCI, like PCI replaced ISA.
Where does SATA fit in? I'm unclear on that concept.