Of course even when Nixon completely detached the dollar from gold we had a very very modified gold standard. But at least there was some tie to reality.
Now we live in an almost completely fiat system, though it can be argued – well – that oil is the de facto backer of US currency these days, the so called petrodollar. (Though some do not buy this argument.) Regardless we live in a highly financialized world with lots and lots of cheap money floating around.