What God promised is that everything that can be shaken will be shaken.
Very likely not this time or the next time, or even the time after that, but then, you never know--why not this time or the next time, or the time after that?
I think that this can be taken on both the macro and on the micro levels--the macro level of economic and political systems, and the micro level of our own individual well-being (which, after all, is macro to each of us!). Maybe the economy will right itself, but each of us will still, after all, eventually die.
How strange that this promise of shaking is actually a good thing--but, apparently, it is:
"But when these things begin to take place, straighten up and lift up your heads, because your redemption is drawing near."
"Lift up your heads, O gates, And be lifted up, O ancient doors, That the King of glory may come in!"