Below is a series of the same study in different time frames. It is a correlation study of the US dollar and the euro. As you can see quite clearly in the daily chart - it took some time for the strong and steady inverse correlation it currently has with the US currency. Post 2002, it is quite rare to see that relationship weaken. We are currently coming through one of those periods on the monthly chart and in one of those periods on the weekly chart.
My best guess is this turbulence in correlation marks an inflection point for both currencies.