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.
Every estimate I have seen is based off already paid for devices. These are not numbers pulled from someones ass, they are based on known variables. And the numbers thrown around for BFL are likely on the low end. The only unknown is when these devices will be delivered. Also just wait til KNCMiner starts production(they have only accepted what? 500 pre-orders?), if they succeed(which looks likely), the network hash rate is going to definitely be stupid high. Next re-target is already estimated at 18.2 Million and 890 blocks are still left. And if the hash rate stays at 150TH, the following re-target would be about 20 million(quite unlikely, I'd put my money on it being 21+ million ).
Their will definitely be a point when the hash rate stabilizes, I'm just hoping not to many devices have been bought and the network is saturated. These devices still use quite a bit of power, so even if they sold dirt cheap, they still need to produce enough money to pay for power and have enough profit to keep operators interested. Before the block halving and the ASIC buzz, ROI was about 6-7 months, I have a feeling we are going to go quite a ways past that and hit at least 12 months ROI, which seems to be above the threshold for operators to keep miners running(at least in the past).