How do I get the Mindstorm EV3 software to recognize an NXT brick via Bluetooth? I'm trying to program my NXT brick via the EV3 software over a Bluetooth connection.  

I can connect it via USB (although that too failed initially, but has since been resolved; not sure why) but I'd really like to do it via Bluetooth as I could with the NXT 2.1 software.

How do I get the EV3 software to recognize my NXT brick over Bluetooth?

Here is a copy of the connection area in the EV3 software showing that the NXT brick is available via USB but not Bluetooth:



And here is the same NXT brick available in the NXT 2.1 software:
Communicating with the NXT from the LEGO MINDSTORMS EV3 software is not supported.
From http://www.lego.com/en-us/mindstorms/support/faq/:

3.10 Is the LEGO® MINDSTORMS® EV3 Home Edition Software backward-compatible with NXT Hardware?
Yes. You can program your NXT Intelligent Brick using the new LEGO MINDSTORMS EV3 Home Edition Software. However, not all Software features are supported by the NXT Intelligent Brick.

It does not explicitly mention Bluetooth, but it is one of features that is not supported.
References:

Compatibility EV3 software with NXT brick - known limits?
http://robotsquare.com/2013/07/16/ev3-nxt-compatibility/