For the past week or so, I've been seeing a lot of chatter around a Google updating happening. The thing is, it is hard to tell what is going on right now.
The WebmasterWorld thread has a lot of chatter that symbolizes an update but that chatter has been pretty steady for the past couple weeks or so. In addition, the monitoring tools, such as MozCast shows higher signs of volatility than normal. Here are the temperatures 73° on June 24, 86° on June 23, 77° on June 22, 71° on June 21 and 72° on June 20. So pretty hot days this week and the week before.
The kicker is on Friday, Matt Cutts tweeted that there is an update being pushed out over multiple weeks. Matt said:
Multi-week rollout going on now, from next week all all the way to the week after July 4th.
The reason I think it is spam algorithm related is because @screamingfrog tweet about a [car insurance] query was what Matt responded to.
I will see if I can get more details from Matt Cutts and will let you know the details when I hear back.
Forum discussion at WebmasterWorld.