The huge WebmasterWorld thread devoted to tracking Google changes over the course of March 2008 has sprung some late March legs. Reseller, well known at WebmasterWorld for tracking the slightest changes at Google, posted two data centers that are very different.
The two data centers that appears to be shuffling around include:
May be the folks at Google Search Quality Team are focusing this weekend at improving the search relevancy at the top ;-)
Google's constantly updating their search index and results, but this update seems to be pretty major. We do not know yet if it will propagate through to the main Google.com results.
Forum discussion at WebmasterWorld.
Update: I am getting word that many folks are seeing the dramatic changes at the main Google.com results. I personally don't see the 18.104.22.168 data center hitting the Google.com results for me, but many are now.