And the other question - heat - what are the plans to deal with that?
Is the silicon going to be exposed (BFL-like) where users can attach a proper heatsink? Or is heat going to be dissipated through the PCB? If the second then bitfury-like packaging with a huge pad underneath the chip (and tons of vias on the pcb) will be better than a bunch of balls/pins.
And my apologies if some of that has already been answered.
The designs for the heatsink appear well advanced, they have samples in what looks like aluminum and copper from last week. I think they still haven't decided on whether to house all the chips in a single 19 inch Prospero-3 (with two rows of boards and heatsinks) or to split this into 2 units with one row in each. I would assume the Prospero 1 heatsink will be identical to that of the Prospero 3, so you will be getting a little Jalapeno/Little Single style unit (due to the size of the heatsink).