The button is gone, but the philosophy behind its existence up until now remains
Those of us who have hopped on the Facebook beta testers group have received a visually-important update to today which removes the legacy menu button. This marks the final disappearance of one of the most annoying parts of the Facebook app, which should not only free up visual space on the bottom of many HTC devices without a capacitive menu key but also fall closer to Google's Android design guidelines. Taking place of the legacy menu key are a full set of settings behind the slide-in left panel.
We're happy to see the legacy menu button go away, but this shouldn't be a complete standing ovation. Facebook has made serious improvements to its app in the recent weeks but still flies aimlessly around most of Google's other design guidelines in terms of using drawers, overflow menu buttons and most standardized design elements. Additionally, we're not entirely sure what other changes have been made in this beta to accommodate the lack of the menu button. Facebook has gotten rid of the visual reminder that its app development was based in the Gingerbread days, but we're not completely sure if the underlying code in the rest of the app still is.
Anyone that is currently signed up to be a beta tester can grab the update on their device now, and anyone waiting for the more stable update should see it soon once any potential bugs are squashed.