The modules page is already quite long with only the core modules but when you add views, cck and other modules you're going to use on your project it becomes unwieldy. I've created a little proof-of-concept module that turns the fieldsets on this page into tabs.

Dependency: http://drupal.org/project/jquery_ui and you need to download http://code.google.com/p/jquery-ui/downloads/list?can=3&q=1.6 unpack it in the jquery_ui directory and rename it to jquery.ui.

If you're interested in this functionality and would like to see some extra functionality, please comment on it and if there is enough interest I might turn this into an official module.

Here is a discussion on how the page should look for D7: http://drupal.org/node/538904