It is imminent because fundamentally it must happen. This is a symptom of a fiat system. Every fiat system has collapsed, but they keep trying it and in most cases to even crazier extremes. 
It's been manipulated off for decades, but it doesn't change the fact that it must happen and as they're running out of opportunities at the Fed and will to go negative to attempt to put it off more, countless countries around the world are swapping out of the USD and it has caused panic in the financial sector. 
I discussed this with Ron Paul in an interview last July. It's not about putting a date on it, it's about stating the obvious.