It might be a tiny reduction, but I think that the start of a new era is now becoming more obvius. We kept seing mining becoming more centralised, mining at home kept becoming harder while the difficulty was constanly rising and the price was around 350. I believe that this reduction was caused by home miner being pulled off the wall because of not being profitable anymore.
It's possible that there was a genuine reduction in capacity, but with this small a difficulty change it's also pretty likely that it's just a result of statistical variances and we have no real way of knowing whether the network is expanding or contracting. In a network where there's no actual change in capacity, variances of +/-5% are pretty likely:
http://hashingit.com/analysis/28-reach-for-the-ear-defenders