I just built an Ion based Myth Frontend. It's awesome:
http://pdavila.homelinux.org:8080/blog/?p=347
http://pdavila.homelinux.org:8080/blog/?p=348

It's a great box for MythTV (frontend), XBMC and Boxee.

I love NeurosTechnology but yeah why the hell did they go with an ATI card? They can still replace it. They're not locked to it by any means.

You can get it working with DishNetwork. You'll need to get an IRC blaster and a second customized version of lirc running to control it. This is required with either digital cable or satellite tv. Here are the links:
http://www.irblaster.info/
http://losdos.dyndns.org:8080/public/mythtv-info/M ythTV_DISH_IR_LED_TX_via_Modified_LIRC.html

I currently have my Myth box connected to analog cable and it works fine. I plan on moving down to the living and hooking it up to my dish network receiver pretty soon. The quality of the show is only as good as your input. Good luck!