it only keeps going up as more mining power is added. if people stop adding rediculous amounts of power to the pool then the difficulty will drop. there were gentlemen's agreements proposed about things like this a while back. They go as far back as the transition from cpu to gpu.
https://bitcointalk.org/index.php?topic=12.msg54#msg54you should have a look at the mining facility he has built already in iceland near the artic circle
its pretty ingenious ,he uses the an air intake from the ice under the building to keep the machines cool
and he gets his power generated from cheap natural sources as well
seems to be a smart guy and he plans to build more of these in differnt parts of the world next year and
already got the funding for a new one in texas opening in feb
you should tell this guy about the "gentlemans agreement "
by febuary he plans to have 15% of the hashing power when he opens his new mining farms
http://ecreditdaily.com/2013/12/bitcoin-mining-iceland-hot-market-cooling-anytime/Lots of miners plan to have 10% to 20% - it doesn't work out for any of them. Its called competition.