Is this the Next-Generation Nexus 7 in the Hangout Promo Video?
Google launched its unified messaging service called "Hangouts" yesterday at Google I/O 2013. To understand this messaging app Google posted a promo video on YouTube. If we clearly see that video (posted below), we will notice a unannounced tablet used in it. That Tablet is expected to be the next-generation Nexus 7 aka Nexus 7 II.
Google didn't announced any new Nexus device this year at Keynote. But we still expect some private event from Google to take place, to launch there this year Nexus Devices and Android 4.3.
Source - AndroidOS