bitcoinwisdom is now showing an estimated +4.15 change with a 1, 3, and 6 block time of 10, 30.1 and 60 minutes respectively
yeah but it is pretty much worthless number under current mining conditions. that huge piece of hash power (all s-3's) is around 50ph and the best explanation I see is owners of s-3's simply turn them on and off based on diff/price numbers.
really makes for tough guess at diff movement. you noted price jumped to 250 from 225 and maybe a lot of s-3 owners power back on. I agree. that is bound to happen. but that www.bitcoinwisdom number does not reflect it to well. not to say they are wrong since they are looking ahead.
http://btc.blockr.io/charts
in a few hours they will give feb 14 block total this will allow the current standing of diff for the first 720 blocks. maybe -2 % or -1% .
then you need to think will price jump from 250 to 275 or drop to 225. all will be a big factor with s-3 owners all over the world.
I think a falling price is causing more S3 owners to turn off their machines then a low price. I don't think many owners want to be selling ~$1.25 worth of bitcoin per day per S3 if they were to leave it on, they would probably want to sell $37.5 worth of bitcoin once per month (per S3) as selling that small of amount every day is almost not worth their time (assuming their intention is to sell the entire amount to cover their electric/hosting costs)
The estimation is always highly influenced by the previous Diff change (previous 2016 blocks) Meaning that if the previous diff was 10%, the estimation will be way higher even if the generation time is 10 min since the change of diff.
The estimation will be greatly close to the reality 2 or 3 days just before the end of the current diff unless a massive change of Hashrate appears.