Yeah, doing that bothered me so much I finally broke down (half a year ago) and wrote an ethernet upgrader tool for Linux. MUCH faster, too!
Yep, somewhere in there I even tried to use it. Problem is that as far as I can tell the builder image never brings up the ethernet interface and I wasn't up for digging up the required utilities and libraries to assign an IP and all that and then transfer them to the empeg via serial. The next time I need to do a regular update I'll give it a spin though.
-Mike