It will never stop!
Probably somewhere in the 80B mark it has to top out.
Estimated Next Difficulty: 29,224,980,526 (+22.56%)
Adjust time: After 1487 Blocks, About 9.2 days
Hashrate(?): 194,989,563 GH/s
of course it stops growing if .5 watts is the best an asic chip does and 4 cents a kwatt is the cheapest big power supply diff will slow or btc will jump quite a bit.
Spec threads are fun. I am pretty bullish about it all and most guy are bears here on bitcointalk spec threads.
I see growth under 20 closer to 15 maybe even 13 this time.
I also do not see huge network growth predicted. here is why. most mining is in the hands of asic builders .
the small guy with 1k to 20k in household gear has less then 20% of the network. I used to sell amazing amounts on ebay not anymore. .
The guy that is doing this with a few paychecks worth of money is spent/tapped/tired of the game.
I still see btc price growth with less diff growth. we averaged 24% for 200 days then 18% for 200 days and since june 29th the diff has been 9% this is for 55 days.
I can't see more then 10% for the next 145 days. Not at 550 or 500 usd a coin. So either diff lowers or price jumps.