Elsmarc - 12:11 pm on Aug 8, 2012 (gmt 0)
Since my main site (a technical discussions forum) was hit hard, and for several years I haven't really been paying much attention, I've been digging in. I thought my hit started on 28-29 July 2012. In looking closer at search queries in Google's WMT there was a slight spike on 24 July. On 25 July it was a "normal" day. On 26 July a small drop. Each successive day through the weekend there was a small drop, but the following week (this week) traffic appears to have stabilized at about a 70% drop in search referrals. It has stayed stable so far this week at that "level".
I'm getting ready to look at my "new visitors" numbers which tend to correlate with search queries to some degree. I do get a lot of direct traffic - It's a very old site and is relatively known in its niche, so I have to try to take that into account.
So far it looks like what @muzza64 said in post 4482487 on page 5 in this thread is what I'm seeing. But as always, just guessing.