Didn't they basically "waste" a whole wafer testing when the testing rig didn't work? Then they had another wafer, which is probably where the ones made so far came from.
Pretty sure that is all they had?
Yes they "burned"(no clue wtf that actually means) their first wafer just to make sure the logic and cores worked properly. They(the Asic designers not BFL) setup a chip(s) in a test rig without bumping it. There are some pictures out there showing the chip with wires and crap coming out of it. (I might be using the wrong terminology for this stuff, please don't flame). From what I remember that wafer had better results then the other chips that were bumped and put on the 5 gh boards/Luke's unit coming from the other wafer.
Again, this is just my understanding of the situation. I just go by what I have read.