Using Quick Response, you can quickly reply without leaving the inbox in Outlook 15. This saves time without having to take some time to reply to messages by going back to Inbox and then selecting which messages you need to reply to that open up the message window. Instead, there’s a right pane for quick reply to whatever message you’ve received in the inbox. Also, there’s the draft indicator whose drafts will be there until you send your response or discard it just like composing the respective messages you want to send to. The draft indicator may make it easy for you to see which messages you still need to act on without switching to Drafts folder or looking around for open reply windows. When you click on a conversation that shows the indicator, you will automatically be brought back to the mail you were composing so you can pick up where you left off.
Well, that’s about it but you can find out the full details of Quicker Replies in Outlook 15 at the official Outlook Blog. Hopefully, they won’t screw up in case.