Close... So close...
Believe it or not, I figured out how to get the ATI HDTV Wonder recognized by Linux!
It's actually a fairly simple two-step process:
(1) First, you have to get the proper firmware downloaded. I followed the instructions here:
The only difference is that instead of putting the dvb-fe-nxt2004.fw file in /lib/firmware, it goes in /lib/firmware/[Linux Kernel Version]. This will be a directory such as 3.13.0-24-generic or some such.
(2) Second, you have to create the proper options file so the OS picks it up. There are several different ways to do this depending on your setup. For mine, you have to create a text file called /etc/modprobe.d/cx88xx.conf. In that file goes the following line: "options cx88xx card=34".
After doing these two steps, reboot. The card is now recognized by Ubuntu.
I've tried MythTV and TVHeadEnd, both PVR capture programs for Linux. TVHeadEnd seems to work better for this application. Once it does a channel scan and finds the OTA broadcasters in the area, those channels are presented to XBMC.
Here's where the problem comes in. If I connect to the z555 from a different computer over the network with VLC, I can view the channels from TVHeadEnd. They are gorgeous! Great playback, great sound. However, when I try to view the channels on the z555 itself, that's where the problems start. First, there's no picture. Second, the sound plays but cuts off after 10 seconds or so.
But I'm really closing in on it! Once I get those issues sorted out, then the PVR function will be licked!
I'm almost the point that I might rename it the z555buntu...