It looks like big things are a foot at Google. I run quite a few websites, a music blog and a few other smaller sites. Recently for one of my sites which posts information about upcoming albums I was getting around 600 visits a day, but as of the 25th of September, 2013 traffic to this particular site dropped dramatically by at least 90%. The site went from 600 visits a day to roughly 50 at present.
Be warned, it appears Google have made some changes to how sites are ranked. I went from ranking first page for a lot of artists and albums to barely ranking at all. I honestly thought the site was penalised but it seems mega spammy sites have managed to remain on the first page of a lot of terms I used to rank for.
I hope whatever it is Google are up too, this is a side effect and the traffic goes back to normal soon.