While I do believe there will be a major US dollar devaluation in the (probably) near future. I don't think it's going to "crash" and become almost worthless like a loaf of bread costing $100. While I know that the US dollar is becoming less important to the world economy, it's still the biggest player and will be for quite a while still.
A loaf of bread in 1900 cost about $0.07. In 2014, about $2-$4 (depending on the loaf etc). It happens gradually so people don't notice overnight it going up so dramatically from $0.07.
:-)