Updated builds of MythTV are available by installing the mythbuntu-repos package. This thread is for questions, issues, etc about the mythbuntu-repos package or the build process itself. This is not the place to post bugs about mythtv or other related plugins.
For 12.04 and future releases this functionality if built in. You can enable it from the Mythbuntu Control Centre on the repos tab.
For releases prior to 12.04, please go to http://www.mythbuntu.org/repos for more information and to download the Mythbuntu Repos package.