I think what's going on right now is that they have realized that they will be unable to maintain their "leader" position in ASIC development and they are trying to milk the network as much as they can delaying the shipments knowing that they will effectively decrease their network share.
And I for one hope that K&C and bitfury devices start shipping on time so then both Avalon and BFL will never ever get another customer.
Answer: Someone who said that around 3.5TH/s of batch II would be delivered in silver cases and only the later people will get the new black design and then delivered almost all of batch II in the new black cases (after being BUSTED publicly on sending silver ones that had been mined for months) might have a very good reason to withhold more miners from diluting the market share they are mining with the amazing missing batch II silver miners.
So are the new Batch #3 miners, magically no longer dusty? Has this been confirmed. As if it has, then they were blatantly mining before.