Hmmm, clearly "some" here are very sensitive when Concorde is mentioned. Yes, a wonderful bird, and is unique...BUT, it certainly is NOT the nirvana of aviation.
And, if a little strip of tin causes BIG problems (as the French investigation indicates)...not too reliable either. Especially when we can clearly see that the AirFrance aeroplane was being operated overweight....just like any aeroplane....CANNOT be abused, or it will bite.
In addition, it was mentioned that GPS cannot be used as primary navigation. Actually, it very definately CAN, at least with US registered aircraft. The JAA may indeed have other ideas, but suspect that they are just jealous that the system is not....theirs.
Having said this...triple INS works just fine, especially when they are Delco or Litton units. Seem to remember the last bit of "reliable" navigation kit to come out of the UK....was the Marconi Doppler.