Hashrate is still ~21 TH/s... didn't it go up to around 28 a day or two ago, or did I dream that??
Not dreaming, you can see it on
http://www.asicminercharts.com.
I do not know if it was a test run deploying new kit. I've noticed in the past when the hash rate goes up to a new high it tends to come down again before retracing up again. It looks like it's climbing now.
Variance. I'll try to get time to post a chart which should provide a better indication of hashrate than a daily average.