An early WebmasterWorld thread is reporting very early signs of changes taking place at the various Google data centers. Often, these types of threads tend to spot a Google update that is about to take place. But it would be cool if Google gave us a Valentines Day update.
Let me stress, this is very early and that Google always updates their results - daily. But this seems to be a larger update.
Here are some of the reports from the WebmasterWorld members:
A well known rank tracking service is showing a huge spike of changes for yesterday.
Looking at various datacenters it looks like Google is "testing or comparing" different series of SERPS, at least for the keywords I'm tracking: September set of results, late october, Christmas time and January's SERPS. Perhaps Google is comparing the filter/penalty/alogo changes we have been seeing against its results from pre-September.
Again, it is very early, but I will track it.
Forum discussion at WebmasterWorld.
Update: Matt Cutts commented below that he does not believe there is an update taking place. Plus, he has a room of SES speakers who backs his opinion. :-)