While Twitter for BlackBerry 10 has been updated a couple of times since its release, Facebook has remained stagnant, both in terms of features and stability. Suffice it to say, it has not been an extremely usable application to date.
Both apps have been updated with improved access to various key features. For example, Twitter now displays Interactions such as retweets and favourites as well as mentions. It also shows Cards, or expanded tweets, with compatible content partners.
Facebook has been given an even bigger overhaul, allowing you to access events from within the app (it previously took you to a web page), the ability to tag users in photos and, finally, the option to share content from your news feed.
Hopefully with these updates the apps can improve their ratings in BlackBerry World; Twitter has 2.5 stars and Facebook has, sadly, 1.25 stars.