Google’s mobile operating system has a lot going for it lately. Adoption rates of Android now appear to top the iPhone, and Facebook CEO Mark Zuckerberg has apparently begun using an Android phone — at least sometimes. And, Facebook’s new head of mobile products, Eric Tseng, has just arrived after helping to lead Android’s development at Google. All of those factors may have played into Facebook updating its Facebook for Android app.

There are a couple of immediately noticeable additions to Facebook for Android. First is the photo stream at the bottom of the app. The stream shows friends’ most recent uploads, allowing side-scrolls to see more or a tap to view a larger version of the picture. The other important addition is an Events button that takes you to your personal calendar.

Unfortunately, one major function is still missing: access to chat. As you can see below, the new Android app one-ups the iPhone version with the addition of the photo stream, but falls short in not allowing chat.

A few less immediately noticeable features added to Facebook for Android include video playback, in-app friend adding and a slightly more intuitive interface.

Unfortunately, the Android app has long been maligned for its half-built state, and users may not immediately realize it has been updated. For quite a while, in fact, the common wisdom held that Facebook for Android was a complete failure — until, that is, we found out that it actually had millions of users. Current AppData stats show it with about 5.5 million monthly active users, to the iPhone’s 61 million.