It could be some miners are hoping for a breaking point.. ie, it becomes so HARD to mine that MOST miners get out leaving only a hardcore group and eliminating some of the difficulty. I for one do not think difficulty will continue to climb.. eventually it will go down and only those few left mining will reap any rewards..
It will climb for a while but its not going to be +33% forever. It will eventually stabilize to a sustainable number.
Agree, anything parabolic is not sustainable, BTC price or Mining hashing power.
If you are right, then Asicminer is going to go bust unless they can kill off the competition somehow.