Comment 1 for bug 600745

In Maverick, I get from rdepends:

aptdaemon
Reverse Depends:
  sessioninstaller
  software-center
  python-aptdaemon
  language-selector

And lucid is
Reverse Depends:
  software-center
  software-center
  python-aptdaemon

Hence, even in Maverick do you get aptdaemon from update-notifier by itself, though you do get it as a result of a default install (via software-center). It also appears update-notifier[-common] can certainly get installed on Ubuntu "server" images by default, but in that case nothing that leads to aptdaemon would be present since software-center is of course not installed, but this circumstances would be desirable there. Since aptdaemon is about user access to package management, and one may not want that functionality if they really have chosen to remove software-center but keep update-notifier alone, I am not sure it should be a recommends, but I do think it could at minimum can clearly be a suggests.