BFL's ASIC can match that if they want. At 40Ghash their ASIC was running at 500Mhz, and they said it can do 1Ghz but not all chips will reach it. So 72GHash is possible.
Not sure how many in this thread read the post referenced by OP, as most people are seeing "ASIC war!" but it looks like this is simply a result of ASIC stability.
Where is the design at now?
The design of the smaller bASIC unit grew from 2 ASICs per board to 6 in a cluster, each ASIC producing 4.5GH/s (safely) for a total of 27 GH/s. As you probably know, digital computers/microprocessors operate using the binary (base-2) number system. This somewhat naturally leads to architectures that most efficiently have their components (such as I/O signals, communications paths, memories, etc.) in quantities of powers of two - 2, 4, 8, 16, and so on.
***Important - please read closely***
It is for this reason that we are going to grow our hashing cluster to 8 ASICs. With two clusters on the larger unit, it will conservatively produce 72GH/s. Yes, this is very good news - a 33% increase in hashing power! Yes, this means the 27G unit now becomes a 36G unit. These initial numbers are conservative estimates, but we expect that firmware and software updates will be able to iteratively increase hashing power as well.
Might be BS, or might be true, that it's simply a matter of the fact that 8 is more stable than 6, and that's why they chose to go this route, which will end up with some happy customers. Rather than being anything to do with outdoing BFL (though that doesn't hurt).
EDIT: Reminder though that chips were apparently literally dying at overclock speeds, so before you have wet dreams of overclocking, keep in mind the horrors of murdering your ASIC chip.