I imagine these bidders are smart people. Which means not one of them would dump the markets with coins and lower the value.
I imagine there's going to be a slow release of coins over time, so that would mean a slow devaluing over the next few months.
The amount of BTCs at auction was only 1 day's worth of traded volume on avg (maybe i misremembererered that but you can find the info on blockchain, its a small portion of traded BTC per day anyway).
If they now sold them into fiat on an exchange at a fraction per day (say <5% of them) it would barely affect the price. They would need to dump most of them at once to really affect the price, and that would take a coordinated effort of all the winning bidders.
Its all speculation and hype, the only real impact this story can have is the psychological effect of the price they sold at (ie if they auctioned for 650$+ per btc then it would probably cause a small buy rally and viceversa) and also
who bought them. If we find out that Goldman sackballs bought them all up for 800$ per coin then we'd be using mBTC format pretty soon. But if coins remain unsold and the ones that did sell went for 450 then we'd probably see a dip. Lets find out what we can on Monday anyway. End.