I've also seen gains of about 15% this week, as compared to the week before. It looks like things started to shift on Saturday.
Normally, my site peaks in traffic on Monday and then gets lighter each day as the week goes on. However, this week, search referrals have continued to increase each day. Looking at Analytics, I'd have to go back more than a year to see a Wednesday that was this much stronger than a Monday in the same week (excluding holidays). Something's brewing.
US informational site.