There is a drupal6 package in Debian, but for me as a Drupal User its support in Debian is somewhat unsatisfactory. Apparently it's not just me, but several other users are in the same situation. Drupal releases new version when a security issue was fixed in Drupal Core. Currently there are several security issues pending that are fixed in newer upstream version 6.15, which was releases on 2009-12-16. Bug #561726 deals with this as well as #562165.
It seems as if the maintainer is busy with other things, which is fairly ok, and if he isn't following Drupal security mailing list as we, as the users, are always need to forward and remember him about the security updates. Not just now, but also in the past. Remembering the maintainer about security updates is ok for me, alas it's somewhat tedious doing so. And beside the current situation, which made be ok giving Christmas vacation, Happy New Year and such, I'm quite satisfied with the work of the maintainer. But: could someone else please upload a new version of Debian in the meanwhile, please?! ;-)
Luigi uploaded drupal 6.15 to unstable and I'm subscribed to pkg-drupal-devel on Alioth... ;)