Today is business as usual for me (friday and saturday a little slower), but I noticed major changes in SERPS for my 2 websites - 50% decline in visitors, 10 days ago.
One website has Google Webmaster Tools and Adsense and other monetizes with Chitika and don't have any Google products. I don't use Google Analytics. I really don't know how this decrease in number of visits starts at the same time on both websites, because they are not connected in any way.
I think that probably was some change in SERP algorithm.