Can I control 2 NXT bricks from a computer using bluetooth at the same time? I am thinking about starting a project involving controlling the movement of a mindstorms robot depending on some input from a Kinect device; however the robot will require at least 6 motors. I have access to 2 NXT sets* (provided by university) - is it possible to control both bricks using either one (or two) bluetooth dongles? I've read through the Bluetooth SDK docs but they only mention that a master NXT can control up to 3 slave NXTs. Reading through the protocol spec I see no reason why another NXT could not be controlled by just sending it "direct control messages". Can it be done in a simplistic way without having to make my own low level bluetooth api?
Yes, this is definitely possible! You can connect up to 7 different NXT devices from one computer and one Bluetooth dongle (theoretical limit). I have tested this with the RWTH - Mindstorms NXT Toolbox for MATLAB) successfully with 5 NXTs on Linux and with at least 2 NXTs on Windows. 

In real life, it depends on your Bluetooth hardware. Your Bluetooth stack or driver software should provide several serial COM-ports. You can then connect each virtual serial port to a seperate NXT device, and access them via those different serial ports. 

If you go the direct way via the official LEGO NXT Bluetooth SDK you mentioned, you can retrieve different handles to multiple NXTs.

Oh, and for the record: You can also connect multiple NXTs via USB, and you can also mix and match with Blueooth.

Regards, Linus