When I navigate the net for new software, I like to see screenshots (eg. LyX, wxftp, xemacs, etc). I presume that users navigating http://www.debian.org/distrib/packages would also often want to know more about a package before downloading it.
A few of these questions could be answered with an extra link to the package's home page (if it exists) on the Debian package's page. The only problem is that this info is not currently included with the packages. Perhaps a new and optional www line in the control file would be a nice addition? Peter