Beyond the added text in a notification and ability to swipe away, comes the ability to delete and reply from the notifications window.
To expand and collapse the notification, pinch and squeeze the notification horizontally. A delete and reply link appears that bring you right into the Gmail app.
To make Gmail notifications more useful, you can narrow down notifications to just your priority inbox. You can specify which senders and labels will be included in your notifications.
Now you can act and respond to important emails quicker and leave the rest for when you have time to preview, read or swipe away in the app.