False, every 2100 blocks. Which is roughly every 12 days. Next difficulty in about a week. Probably will be around 800k.
Difficulty can also drop if enough people drop out. At these prices though, I highly doubt people will drop anytime soon. If the market tanks we will see people dropping out.
Off by two orders of magnitude on the adjustment, good to be wrong. How would difficulty drop if enough people drop out? Is there a safeguard to do that if too few blocks are being generated? That was my concern -- if it takes 10 days to generate 2100 blocks at a difficulty of 560k then how long would it take if just about everyone dropped out at once? Right now pool capacity appears to be growing by 20% a day for the 3 pools I looked at.
I think 800k may be a bit conservative for next week looking at massive pool capacity growth.
And speaking of pools, I'm getting much higher payouts in BTCGuild as opposed to slush's pool. About 15% better over 12 hours looking at a parallel test with one 5830 in slush's pool, one 5830 in BTCGuild. I've converted both of my miners to BTCGuild as of now.
I don't really have an explanation for this, except I've noticed my payout per block in Slush's pool declines the longer the block takes to solve -- a double whammy. He seems to weigh the work submitted right before the block is solved much, MUCH higher than all the other work. Or someone's figured out a way to game his system. I get consistent results in BTCGuild, so between less flakiness, support for long polling (about half as many rejected blocks) that pool works much better for my hardware.