I don't think they were planning on getting to 4PH on Avalon chips.... you would need your own power station.
The part of the article that didn't make sense to me was the "supercomputer"? A super computer would be crappy as a hasher compared to an asic.
Maybe the whole article is full of crap... /shrug
Even if they get better chips, the hash rate is rising faster than Moore's Law, which works on hardware performance doubling every 18mths. I don't think ASIC mining scales to suit big farms. I think it is best for home users with no staff or rent overheads, I might be wrong, but so far none of the big projects make sense on paper unless BTC/USD starts doubling in price every few months.
I bet when the big farms made their plans, they didn't know about KNCminer, Hashfast, Cointerra, BFL 28nm etc.