Credit:
Although this makes the app far more complete and (finally) up to par with Facebook for iPhone, Android users still have a lot to be grumpy about, as the push notifications only refer to chat, not other events such as comments and likes.
Furthermore, since only 43.4% of users are running Android 2.2, it means that a lot of users out there will miss out on push notifications. For comparison, iPhone users have had push notifications since January, and the feature works on both iOS 3.0 and 4.0 devices.