This soon-to-be-released Nikon WR-T10 wireless remote controller appeared on the FCC website.
From the published manual, it seems that the WR-T10 can remotely trigger up to 64 separate cameras that can be grouped in 3 different channels. A separate adapter for each camera is required. This solution would work also with older cameras with a 10 pin adapter:
With a WR-R10 (transceiver) connected to the ten-pin remote or accessory terminal of your Nikon camera, photographs can be taken by remote control using a wireless WR-T10 (transmitter). The WR-A10 is a ten-pin remote terminal adapter for the WR-R10.
The following options are available with multiple WR-R10 units, each mounted on a separate camera.
- Using a WR-T10 (Simultaneous Release): If the WR-R10 units are paired with and on the same channel as a WR-T10, the shutters on all cameras can be released simultaneously by pressing the WR-T10 shutter-release button all the way down.
- Synchronizing Multiple Cameras (Synchronized Release): A WR-R10 mounted on a camera with ten-pin remote terminal can be used to control WR-R10 units on multiple remote cameras.
The remote cameras can be divided into up to three groups by selecting different channels for the cameras in each group after pairing and then changing the channel for the WR-T10 or master WR-R10 to control only the remote cameras on the selected channel.
Nikon WR-T10, WR-T10 and WR-A10 manual (direct link to PDF):