In order to assuage concerns of Windows Phone 7.5 device owners, Joe Belfiore has tweeted saying that the features which we have seen in latest Facebook Beta will come to the WP7 devices via Facebook update.
— joebelfiore (@joebelfiore) December 4, 2013
For your information, the latest Facebook Beta brings some really cool live tiles and improvement in reliability of toast notifications. I have used the latest Facebook Beta on my Lumia 925 and I am really impressed with all the improvements I can notice. While, the Facebook Live Tiles now shows more detailed information, one can even pin the Facebook pages one administers to home screen as Live Tile. Apart from that, the toast notifications really work well for the very first time in my experience.
• Faster and more reliable notifications • Toasts for Facebook chat • Redesigned primary tile • Redesigned secondary tiles for chat, events, groups, pages, and photo albums • Messaging improvements • Performance improvements • Support for additional languages