Its going to be exponential until it isn't.
I can't tell if I am being overly optimistic or pessimistic, but I anticipate that it will be exponential while all the current 28 nm projects are still in the process of shipping out their pre-orders... so until February or March of next year. Global network hash rate at time will likely be close to 14PH/s. Assuming 41M daily additional difficulty gain for the linear phase (currently we are at 1.5M daily additional so about 27x more hash power will be added daily due to the newer tech available), I modeled a 400GH unit arriving in mid October generating ~ 55BTC of the next 14 months (and a 520GH unit generating ~70BTC). If received Oct.1st, the numbers looks like 75btc and 90ish (for the 520 GHs spec).
Curious how close to reality that ends up.
It's true it won't last forever, but the severity should not be lightly taken. We're just seeing the ripple in the surface with the tsunami beneath.
The visual model I came up with long ago is essentially a modified bell curve of sorts. We're just beginning to enter the rise portion, the +3SD range. We'll pass the +2SD at the end of the year, and my prediction is the first quarter, maybe second quarter as well, of 2014 will be the +2SD to +1SD "sharp rise". At some point beyond that, once all manufacturer's backlogs are cleared out, there will be a plateau of sorts. I doubt it'll be short like a normal bell curve, but it will plateau. I predict thereafter will be a drop off at some point, but not level with the initial inclination. Likely only going beyond the 1st deviation, at which point it'll eventually go up again and will then essentially be a sine curve from then on out with slight variances.
So far my past few months of difficulty predictions (numbers) have been almost spot-on. I'm not an oracle or anything, but I have a feeling my visual model is spot-on with what will happen long term. Picture the histogram on mining.TGB as the window rolling up to the +3SD point of my curve.
As for SHA altcoins, I've been having good luck with PPCoin lately. There are other ones which folks have done well with.
320*1.3 =~ 433 not 520
Roi in 2020
Does being that stupid actually hurt?
I understand where he's coming from. The original clock rate was 320. He's presuming they're talking about an additional performance on top of the original clock rate. However, that's not the case. They adjusted the stock clock rate to 400 in one of their announcements. So he's wrong in saying 320, but I can see why he thought that.
No, the original target rate was
250.
And the new one is 400 ... he's still wrong
I couldn't careless about any cost eating case 
Now that would be partytime. 
