John,
 I think you nailed it, as usual.
 You said, "So in the short run, not much. In the long run a loss in the ability to export inflation will over time affect the prosperity of the US compared to what it has been in the past."
  Yep, nothing this large happens immediately.  IF I can recall from memory, the first reserve currency, i.e., one used by the known world, was Portuguese.  They lost it be cause although their ships (and navigation skills) were superior, they never had enough population to support a worldwide empire.  Anyway, the next one was maybe Dutch?  Then France, then the British Pound until somewhere between world wars.  Then the US dollars took over and will last....until it doesn't, at which point our standard of living drops substantially and we all discover that debtor nations really don't have power.
  Take care.  Stetts