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.
I think you are absolutely right. Some of the forecasts around here get to insane numbers not realizing how much hardware would be involved in gaining such astronomical hashes per second.