What should be implemented/improved?
Most of the time users will want to either search for a specific selector, property or a value inside the CSS panel.
So it would make sense to add three new options "Selectors", "Properties" and "Values" (checked by default to keep the current behavior as default) to the search options panel to allow limiting the search to one of them.
1. Open Firebug on this page
2. Switch to the CSS panel
3. Uncheck "Properties" and "Values" (not existing yet)
4. Type "cursor" (without quotes) into the search field
=> The search should find one matching selector ".cursor_on .author", but not the "cursor" properties (or values containing "cursor").