Thanks for your feedback everyone. Obsessed2, this is actually my second broken device, the first was the iRex, which is only broken in that it has no 3G and there's a spot on the screen.
I've tried to reflash several more times, once with each of the zip files mentioned, but had no luck. The device no longer goes to the "updating" screen, which indicates that it is trying to apply the firmware. Instead, it displays the inverted logo, goes from one to three dots, and then e-Ink side flashes for about 30 seconds, before switching to the Initializing screen. The LCD side continues in the inverted state, as shown in the picture below. Any more ideas?