When you receive a notification banner, pulling down on the handle will reveal added functionality. This functionality will vary based on the application sending the notification.
Here's a few examples:
A Messages notification gives you the ability to Quick Reply and a Calendar invitation can be accepted or declined.
A Mail notification lets you quickly trash or mark the email as read and when receiving a Reminders notification you can mark the reminder as completed or snooze it.
Apple says that third party applications will also be send notifications with customized actions. For example, a Facebook notification might let you Like or comment on a post.
Notably, these action buttons are also present on the lockscreen. You need to swipe a notification to reveal the action buttons.
In iOS 8, Apple has added contact shortcuts to the multitasking interface. Double press the Home button to bring up the interface. You now notice a list of circular contact icons along top, above the row recently opened apps.
Apple shows you the contacts you've most recently talked to. If you swipe to the right, you'll also see your favorite contacts.
Tapping a contact slides the contact image to left and brings up small icon shortcuts to the right offering the ability to quickly call, message, FaceTime video call, and FaceTime audio call.