* We want users to opt into the latest version if at all possible
* We would rather make the decision for users by automatically upgrading them versus leaving them vulnerable and unsupported
* Certain classes of users can't upgrade to the very latest
** For Firefox 4, that means users on PPC machines or Mac OS X 10.4 and below
* Certain classes of users will never be able to upgrade
** Older/unsupported Linux distros
** Users without admin privileges
== Communication channels ==