I am wondering the same thing about 2 Arduino BT units.
I want to have 2 Arduino BTs running the same script that collects sensor data and passes them on to MAX/MSP (in windows Vista on a PC with a bluetooth dongle).
Does anybody foresee obvious obstacles to getting separate sensor data from 2 Arduino BTs in this way?
My guess is that setting up separate COM ports for the Arduino BTs should be easy (touch wood). However, I am using a Firmata-based script for the Arduino and this relies on MIDI for passing the data on to MAX/MSP, so I will need to adjust the scripts to ensure the 2 Arduino BTs are using separate MIDI channels.
Any advice would be much appreciated as I am holding off buying a second Arduino BT at the moment due to my uncertainty.