Over the weekend, in a WebmasterWorld thread that is tracking the Google February 2008 SERP changes, the recent discussion is around a new Google update.
This Google update is reportedly impacting the search results in the position two, three, four and five slots for "some "big" search terms," said Tedster, WebmasterWorld administrator. Member Attomic first reported this by saying how unusual it is to see the results move for the search terms he watches:
I've seen some big changes in the 2-5 positions for a search term. They've been moving around and changing positions for a few days. This has been a verrry stable search term for a few years now or I wouldn't even bring it up.
Senior member, BillyS, is convinced that this is a temporary Google glitch:
I'm convinced that Google burped at the end of January and spilled some of its index. For many months we were on a steady climb then traffic dropped by 40% overnight.
This along with the continued agony over what appears to be a Geotargeting or filtering bug is driving some SEOs and Webmasters a bit over the wall.
Forum discussion at WebmasterWorld.