In a feature akin to Apple's auto-fill texts on 'roids, Smart Reply will learn how you respond to certain types of emails, from certain people, and adapt accordingly -- giving you several auto-options ready for quick release. Like the police guy from Terminator 2: Judgement Day, Smart Reply is constantly changing and acclimating to the world around it, learning how to best take on anything it comes across. Just with fewer swords for hands.
Slumber-centric jokes aside, this feature promises to be immensely useful when corresponding on the go with your smart phone -- when all you've got is two thumbs and nothing to say, anyway.
Here's the word, straight from Google: "Smart Reply suggests up to three responses based on the emails you get. For those emails that only need a quick response, it can take care of the thinking and save precious time spent typing. And for those emails that require a bit more thought, it gives you a jump start so you can respond right away." You'll need to download Google Inbox and check back later this week to take advantage of the new Smart Reply addition.