Sure. But the Sheevaplug (same SoC) is now 3 years old, and it looks
like the whole 'plug-computer' thing never took off. Since phones
seem to be the only consistent market for fast Arm SoCs, we're likely
to see one with usb3 before gbe. But I'll shut up now in deference to
somebody with actual experience.

I'm pretty sure what you're saying is at least partially true, if not even more. I'm also still not sure even these current crop will suffice. But if nothing else, there is at least now a springboard, so at least whether it make sense to jump off it will at least be more tested.