Never underestimate the power of greed.  If you listen to some of the talks at the Bitcoin conference.  This latest round of ASIC's is just the tip of the iceberg.  China is just starting to ramp up its production of cheap ASIC miners for the masses.  Also Litecoin ASIC's are just around the corner.  If anyting, the 4 PH/s jump we have seen in the last 3 weeks is just the beginning.