Chase says Firefox is dropping the .zip builds. The comments on that post alone ought to be enough to get them to bring them back.
I’ve been using them since I discovered that the unattended/silent install didn’t work as advertised. They claimed to have fixed that bug, but I haven’t had time to look at it yet. I’ve gotten addicted to the easy plugin install method of just copying the contents of the previous plugins folder over to the new install and going on.
I’m handling this update using the low tech method mentioned in the forum thread: Install in new directory on one machine, copy directory to server, treat like a zip build.
That works for now.