debian-cd is actively maintained by a team of people, a mixture of the initial developers and assorted users including the debian-installer team. The main repository is stored in a subversion repository on Debian's alioth server, where it can be checked out anonymously as
svn://svn.debian.org/svn/debian-cd/trunk
debian-cd is also packaged and distributed as normal as a debian package. Be aware that the version of debian-cd needed can depend on the target version of Debian for your CDs, for example building etch CDs will need either a checkout from subversion or the very latest packaged version. Debian testing versions are a moving target!
debian-cd development and support happens on the debian-cd mailing list; see http://lists.debian.org/debian-cd/ for archives and details of how to subscribe.