Facebook is moving in a rapid pace updating its official app in Windows Store. Last week, they added support for controlling notifications. In the recent update, they have added a bunch of welcome improvements. The most notable ones are the support for Share Charm to share content on Facebook, IM-only snap mode support and picture messaging. There is also an option to download a photo to set as your profile photo or lockscreen photo.
I wish Facebook can also take Facebook app for Windows Phone 8 under its development to release frequent updates.
Download the update from Windows Store for free.