That would be HOT. I'd love to plug such a thing into my A500. I always wondered why someone didn't just make a board which went into the 1200's accelerator slot, had a USB2 cable at the other end, and essentially made the 1200 a slave to the modern machine on the other end. USB2's bandwidth exceeds anything happening inside the 1200, it could just see the other box as a really fast accelerator. But at that point, why not just do a little Atom board on a trapdoor slot size form factor?
Even looking at the Efika's 700mips speed-that's more than twice a Cyberstorm's oomph, plus it has PCI. Someone could make a CPU board based on its design, with the hangup being big box Amiga CPU slot>PCI interface. Then you'd even have all those little Efika extras-legit ethernet, IDE, decent sound-the gang's all here. The Efika was $100, seems like an accel based on it wouldn't have to be much more than about $300. And it would even run super cool! Just blue skying here..