Starting with the Hangouts app, it now supports SMS and MMS. Google revealed last week that this integration was coming, so it's not really a surprise, but it is still a highly anticipated feature. Now you can send and receive text messages directly from Hangouts. You can even import existing messages, switch between SMS and Hangouts and start group MMS conversations.
Other new features in the Hangouts app update include the ability to send animated GIFs, share a location in conversations, and share what device you’re on and current mood status.
As for the Google Keyboard, also known as the stock Android keyboard, it has received Emoji. Specifically, "inserted emoji entry point and layouts". But it's only available for KitKat devices. While it's a bummer that everyone on Jelly Bean or later still has to wait for Emoji, at least there will be an extra treat waiting for them when they do get the latest and greatest Android OS.
Other new features in the Google Keyboard app include rationalised punctuation across different sizes, space-aware gesture typing, simplified mini keyboard, and more.
Happy downloading (and communicating - the Google way)!