Trudging forward I ran into a couple issues:
The wiki doesn't say how to make scte65scan. I checked the INSTALL/README files and you need to do make -f Makefile.hdhr (the file you have us edit). Easy enough, but you might want to put that in the wiki.
Under the final download and compile block you have libtext-csv-perl and and the comcast_update link. One is an apt-get, the other is just a script - no compiling.
I was unable to apt-get install libtext-csv-perl. A bit of digging showed it's trying to pull a version that isn't there. I was able to wget and dpkg -i a slightly newer version, but I'm not sure why apt-get doesn't have the correct version, even after apt-get update.
However, the issue stopping me is running comcast_update --configure:
# comcast_update --configure
Config File /root/.comcast_update/comcast_update.conf not found. Running --configure.Where should I save the configuration file [/root/.comcast_update/comcast_update.conf] ?
Attempting to connect to mythtv database...
Enumerating video sources...
DBD::mysql::st execute failed: No database selected at /usr/local/bin/comcast_update line 485, <STDIN> line 1.
DBD::mysql::st execute failed: No database selected at /usr/local/bin/comcast_update line 485, <STDIN> line 1.
I'll keep digging to see what is going on, but hopefully this will help others and maybe someone can help me get comcast_update running.