Luck seem to be doing what it does best, being unpredictable.
I wonder if the recent rise in the BTC price has brought some equipment out of retirement, which may account for the increased hash rate, however any idea of the hash rate staying stable is misguided when you bear in mind that Bitmain are about to start shipping new .5TH/s units.
I would predict a large increase in hashing in about a weeks time; this means that for difficulty, at least in the next few months, the only way is up.
I think when I ordered my two S3's the ship time was from July 10th to the 20th, so they will probably dribble out some. Probably a slow ramp instead of a quick jump. I plan on phasing out and selling my S2's and replacing with S3's also so the jump might not be as dramatic.
Edit: My S3 order was from the first batch.
