As far as I've heard from numerous forums, the Nexus 7 isn't receiving Miracast support. Although you should be able to send images and videos to some Netgear or other devices via DLNA, screen miroring doesn't seem to be supported on that device. Miracast works through a certified high-bandwidth WiFi assembly that connects directly to a miracast receiver sans a WiFi network. So far, only the Nexus 10, Nexus 4, Samsung GS3 and Note 2 have the necessary components to mirror their displays using Miracast. It seems the N7 won't be getting it, but here's hoping someone figures it out somehow.