Sofar I've heard nothing that would even suggest the A1X1K to be even close in performance to the top-notch G5-Apple. Depending on the CPU actually used and considering that the 2nd core will lay dormant for the forseeable future it might even have problems competing with 3rd-part G4-modules available for G4-PowerMacs.

Sure G5 aren't supported and it's unsure if they ever will be, but once replaced the NVidia with a (reflashed) ATI card a port should become possible (and surely not harder than for the A1X1k).