rlange - 2:34 pm on Jun 9, 2011 (gmt 0)
I think there was a re-gen of sorts starting late on 6th Jun, it's consistent with the serps upheaval reported in many places. But of course I might be completely wrong and the delay in the site getting back was something else.
Something happened, definitely. My company's main site saw a significant increase in traffic starting Monday (June 6th).
The odd thing, though, is that no changes were made to the site and the new traffic is all going to a different section of the site than the traffic that was lost.
If I had made changes I'd agree that it was a simple re-run of the algorithm, but since I didn't change anything I can only think of three possibilities: 1) Google changed something on their end, 2) some external signal for our site changed dramatically, or 3) the algorithm can produce [significantly] different results each time it's run.