I am starting this discussion to post information for testing the Px4 platform.
Most of the discussion is currently in the APM vs Px4 thread. ArduCopter on the Px4 is a work in progressand has made great progress. I have Arducopter on a Px4 Fmu board
Timecop's port of Multiwii to STM32 should work on the PX4 with some changes to put the mpu6000 in to I2c mode and use it as a Mpu6050 ,or a new Multiwii driver for Mpu6000. The latest version of his Naze32 is using the Mpu6050, HMC5883 and