Correct me if I am wrong.. BTC price has no direct impact on difficulty. Only hashrate, and that is not going to go down.
If network hashrate went from 3500 Ths to 5000 Ths in November (15k increase, and difficulty went from 400M to 600M)....
And.... in the first 18 days of December, hashrate has increased from 5000 Ths to 9000+ Ths.(additional 4000+ and counting Ths's, with expected difficulty rise to 1.1B or so, up ~300M, due in a couple days.
And.... there has been few large shipments of new equipment(is that right? Maybe some Antminers or cubes?)
Then.... Where is all this hashing power coming from? 5 Petahashes in 3 weeks? MY assumption is that one of, some of, or all of (Neptunes, Prosperos, Terraminers, Coincrafts, Sierras etc..) are coming online as we speak, i.e. for testing or flat out raking in BTC.
If hashrate increases are coming from bitfury chips and old idle eruptors/hobbyists, and all the new equipment is truly still in production to be shipped as scheduled Q1 (or not, lol), difficulty will go absolutely crazy, and be much, much higher than the 30% increases going forward the next few months. Does anyone have an educated guess as to how much hashing has been preordered?
However, I don't think that's the real picture. This spreadsheet has been pretty good so far
https://docs.google.com/spreadsheet/ccc?key=0Auya3iRE6az1dDc0UVgwMU52YVpTazVjSHByOGNiWHc&usp=sharing#gid=8 (I'm sorry I don't remember the author, but thank you!)
Even if it's slightly and self-admittedly pessimistic, I see no reason to believe it's not going to be a decent ballpark estimate going forward, which means to me, all(or alot of) the new equipment promised/paid-for is already hashing, and more coming online everyday, and going to continue until sometime in April, when the manufacturers decide they are done teasing everybody with those fashionably late "February Batch" or "Q2" machines, and they decide to start production of their first petahash units. At which point they'll empty the warehouse a little more freely, fully knowing those units are almost useless.
So, my guess is that it would make sense if the difficulty increases will be close to 30% near-term with an upside bias (So Jan 1 guess something like up 500M, then 600M, 700M, and 800M until everything is hashing (yet, we won't have, or will slowly get, all that new hashrate)
But "IF" that spreadsheet is even close: You'll lose thousands in 12 months of mining with even top-of-the-line equipment (even if it puts out more than advertised), at which point electricity costs exceed returns, and you have to throw it out.
http://mining.thegenesisblock.com/a/f56883f7cb UNLESS.... BTC goes back over $1000 and you manage to break even. (That could be stressful depending on WHEN , or possibly "if", it goes back over $1000)
So I still don't know the answer, but I do think the game is rigged to some extent.
Big question for me is "Is this the pipe dream, carrot dangling, get rich quick scheme I've been looking for?" Or is it truly history in the making. Whats after 28nm 500ghs asic chips? Where does the technology hit the wall? Are they gonna let me pre-order these 14nm cpus they'll be stuffing in my smartphone in 2014 that can hash as well as any ASIC chip and tell me I can get a group buy for 100 of them for $25 ea so that I can populate my wasp and hive with, getting 2 gazillion hs's? But hey, if BTC is $100,000, that's a deal maker, right?