nicht getestet: Themepacket module helps Themers and Developers create and override theme implementations quickly and naturally by eliminating the need to manually register theme hooks in your modules and themes. This module will also discover any assets found with your theme implementations (css, js) and drupal_add_* on your behalf.
natürlich will man das gegenteil, nicht ical/rss-links entfernen, sondern microformate hinzufügen... aber da steht, wie's geht
With this, we have a form at admin/build/themes/settings/myTheme with a checkbox that allows us to enable all module css or disable all module css and a series of checkboxes that lets us selectively turn module css back on when all module css is disabled.
I sometimes run into people on the Drupal IRC channels that have a theming issue they just can’t fathom – dysfunctional CSS. Some poor guy has overridden a core CSS class, but his styles just don’t work. I’ve been there myself before and I know it can be very frustrating.