Starting with 12.04, the Mythbuntu team will only be doing LTS releases. See this page for more info.
Enable MythTV and Mythbuntu Updates repositories directly from the Mythbuntu Control Centre without needing to install the mythbuntu-repos package
This is the first release with the LTS HW enablement stack. It will support newer hardware than the old Mythbuntu 12.04 release. For more information see https://wiki.ubuntu.com/PrecisePangolin/ReleaseNotes/UbuntuDesktop#LTS_Hardware_Enablement_Stack