Although most of the changes are "under the hood", this is an important update.
I am most grateful for the Bugfix which adds Firefox Compatibility flag to unofficial branding, meaning that Outlook.com now goes directly to the Inbox when opened instead of providing a "Please update your browser" page.
Details about the update are available here (http://forum.palemoon.org/viewtopic.php?f=1&t=4328).