See http://drupalcontribstatus.com/ for a demo.
A module to help power a dashboard sort of like this, leveraging as much as possible off of the fabulous http://drupal.org/project/upgrade_status module!
If you want to use this code for your own tracking site, feel free. To catch obsoleted modules, you'll need to apply the patch at #303588: Show suggested replacement for obsolete modules to Upgrade Status.
Want to check a whole crap-ton of modules but don't want them installed? The http://drupal.org/project/update_advanced project has an option to scan disabled modules as well.