So could you tell the difference in a blind taste test ? 
Yes ~ usually and provided both samples of cheese are properly ripened.
The "Waxy" stuff is actually the rind of the cheese created by the deliberate addition of a bacteria into the process. Many consider this to be the best bit of the cheese (either of them).
Both are made from unpasteurised cows milk (so don't eat them if you haven't had a TB jab). This applies in most of Europe but in the USA and Australia the law demands that the milk is pasteurised.
Brie is normally "built" in layers whereas the process for Camembert is different, one being poured "whole" whilst with the other the curds are generally cut and then pressed. The "ageing" time is also slightly different hence the difference in flavour with Camembert being a bit stronger in flavour. Neither cheese keeps due to the unpasteurised milk and both should be eaten within a few weeks of reaching ripeness. As DS says Camembert does smell of ammonia as it gets older and once it starts that either eat it soon or throw it away.