I've looked into this briefly and from what I gather, any device that supports WIFI direct should be able to do this. I think I read somewhere that the N7 has wifi direct. Miracast is only a standard. There are other non-standard devices out there that can also do the same thing, but requires changes to the core android files.
Search for xbounds on youtube and the internet. You will see some demos of it. it requires an hdmi dongle that has wifi on it that communicates with your device.
In any event, if the N7 doesn't support miracast, it will support xbounds via a custom ROM (if and when somebody decides to build a custom ROM with xbounds integrated). Then all that is required is the xbounds dongle. Unfortunately, there is not much information on xbounds and when it will be released.
Nexus 4 Stock
Samsung Galaxy Note 2 Stock
Nexus One CM7 (Retired)
HTC G2 CM7 (Retired)