I think the dollar has a lot of inertia so it might reign for a long while longer as reserve currency, but then I also think about how much debt we have. Our treasury can not account for $21 trillion (ref: Catherine Austin Fitts http://solari.com) and the amount of consumer, educational, real estate, etc. of debt worries me, but: I expect a slow burn of our economy, not falling off of a cliff, economically speaking.
We can adjust to a decade long slow downward economic trajectory, people are resilient.