Well, I managed to get it installed properly. Here's how:
Instructions tested on Ubuntu 10.04.4. The HDHomeRun Add-Ons DO NOT WORK on Ubuntu 12.04.3.
1. Install HDHomeRun Drivers:
> sudo apt-get install hdhomerun-config hdhomerun-config-gui
2. Install HDHomeRun Add-Ons
> sudo apt-get install python-software-properties
> sudo add-apt-repository ppa:tfylliv/dvbhdhomerun
> sudo apt-get update
> sudo apt-get install dvbhdhomerun-dkms dvbhdhomerun-utils
> sudo service dvbhdhomerun-utils start
3. Install TV HeadEnd:
> sudo apt-add-repository
http://apt.tvheadend.org/stable
> sudo apt-get update
> sudo apt-get install tvheadend
(Note that currently the repo does not work, so do this instead):
> sudo nano /etc/apt/sources.list
Add the following line at the end of the file:
> deb http://apt.tvheadend.org/stable lucid main
Then hit CTRL-X, and then Y to save and exit.
> sudo apt-get update
> sudo apt-get install tvheadend
4. Restart TVHeadEnd
> sudo service tvheadend restart
5. Access TVHeadEnd using a web browser:
> http://IPADDRESS:9981
I'm now configuring. If I get everything working, I'll post a complete guide.