An ongoing WebmasterWorld thread has some chatter around an increase in GoogleBot crawl activity as well as some early ranking fluctuations.
That and we are just about the 30 day mark from the previous Google Panda update, Panda #24, we are suspecting a Panda update is about to be hitting today or tomorrow.
Normally, days before a Panda update is announced by Google, we see this type of chatter and GoogleBot activity. The issue is, it has been almost 5 months since the last confirmed Penguin update, so webmasters are unsure what is going on with that.
That being said, Mozcast showed some activity the other day, so did SERPs.com, however SERPMetrics doesn't show much, and now DigitalPoint shows changes (See "Search Engine Rank Changes") also but nothing crazy.
Is a Panda refresh about to hit us? I suspect so but only Google can confirm that.
Forum discussion at WebmasterWorld.