Google will be gradually updating Gmail adding so-called quick action buttons that tie in with services offered by schema.org. These will allow users to easily perform some common tasks such as checking in for a flight or RSVP-ing to an invite, all directly within the e-mail.
According to a posting on Google's developer blog these new updates will start rolling out soon and they will gradually include more and more users.
Folks can look forward to using these on click buttons for a myriad of scenarios. Among them is the ability to quickly access flight information when you receive your digital airline ticket. You'll have access to real-time flight info as well as the ability to quickly check in.
Another scenario involves a user receiving an invite and being able to RSVP directly within the e-mail. You'll even be able to do this directly from the main Inbox panel. It's all about Gmail surfacing important info so users don't have to dig around in e-mails.
These new features are open to developers so basically folks will be able to implement different "one click" actions. All devs have to do is add schema.org markup to their e-mails/newsletters and configure what type of actions users will be able to access.