They aren't dumb.  There is significant more power in the act of *retaining* control over such a large portion of total  Bitcoins.  They aren't going to waste it on some silly short term price crash dumping.  The real threat here is that the Government now controls a big portion of all Bitcoins.  That's pretty much the very OPPOSITE of what was intended with Bitcoin.

The goal should be to delete those coins from the system completely, and kick them back into the mining queue to be re-created into the network.  Absurd, I know, but I can't think of anyone who would be unhappy with the outcome of this idea.