According to the MythTV list, the debian packages have a new home.
//deb%20ftp://ftp.nerim.net/debian-marillat/%20sid%20main
which is already listed in the /etc/apt/sources.list from pluto, but do not get to excited, I already tried to upgrade and it wants to remove a few of plutos core packages and there are numerous dependencies that are not available.
I do not know how this is going to effect the future upgrades, but I thought others might want to know.
Rob