Firefox/Feature Brainstorming:Software Update

Automatic updates

For those who opt out of auto-update, provide a "remind me later" feature
Allow users to select type of updates they want (security? feature?)
Allow users to revert to previous version
Better background downloading support (i.e. background downloads using idle bandwidth, easy on Windows with native pieces, harder elsewhere afaik)
Enable users to "bundle" extensions, bookmarks and other profile preferences into a package which can be deployed on multiple systems easily.
Make automatic updates work on Windows without need for logging in as administrator — automatic updates service or scheduler task.
Make the automatic updates feature optional at build time. Some users would prefer their system's package manager to handle software updates.

Regarding the "Help" -> "Check for updates" function: When no updates are available, Firefox tells the user that it may check periodically for new updates without giving any clues or functions on how the user can tune this functionality. I suggest to implement a UI regarding the setup of the update policy here so that the user right there in the dialogue box can tune the update policy without needing to open the Options dialogue box.

Make manual updates work on Windows (and possibly other platforms) without the need for logging in as administrator - possibly by using the above mentioned automatic updates service

The update system should notify users about features implemented in the new versions.
- Security updates: when some flaw(s) is(are) no longer kept in secret, the updater must display the list of threats, color-coded severity, etc.
- Major updates: display the list of new features.