We are living in a weird time - typically when I see the community begin talking about a potential Google update and it is real - the trackers, such as Mozcast and others, will light up the next day with signs as well. But in the past several months, the tracking tools and the community have not been on the same page.
This week, specifically the last few days, Mozcast, SERP Metrics, Advanced Web Ranking, RankRanger and Accuranker all reported fluctuations in Google's search results.
But honestly, the community is very quiet about any update. I see people talking about the trackers showing an update but very few are saying their sites were impacted over the past few days, like the tools show. We did see some chatter a week or so ago but Google kind of dismissed it.
It has been a very weird six months of where the community and the tracking tools are out of sync.
Forum discussion at WebmasterWorld.