Notification Center is getting even more powerful in iOS 8, adding in the ability to reply to and take action on notifications from both the lockscreen and top of your screen. In iOS 8, when you receive a message and it drops down from the top of your screen, you can swipe it down and reply without leaving the app that you're currently in. This works for Messages, but also third-party apps — think about replying to emails or commenting on posts from Facebook right from the Notification Center. If you don't want to reply to a message right away, just swipe it up and it disappears.
If your phone is on the lockscreen and you receive a notification, you can now take action on it without even unlocking the phone. You can accept or decline a calendar invitation, for example, by swiping the notification to the left and tapping your choice. These are features that have been long-time Jailbreak fixes, but now they're baked right into iOS 8.