Well, this version, 22.214.171.124, was released 2 days ago with some security bug fixes. Nothing's new. You can see the list of bugs that have been fixed here.
I've just built this release with Thai icu word breaking patch on my Kubuntu box today. If you're using Linux and want Firefox with Thai word breaking ability, you may find it here. Please be sure that your box has gtk2, pango, pangoxft and icu.
Have fun :)