A SEO friend of mine pointed out that traffic and impressions have gone down signifigantly the past 4 days for ALL of his sites, both personal and for clients.
I checked myself and saw the same thing in Google Webmaster tools. My impressions and clicks have gone down by about 1/3rd - and i'm seeing the EXACT same pattern for all sites (both personal, clients, and even friends I dont work on) in my Webmaster tools accounts.
I wasn't able to find anything on google about this OR matt cutts twitter feed.
Anybody noticing the same thing, and if so - have you heard anything about it?