On the last day of March, I reported on a major Google search index update which seemed to have impacted tons and tons of SEOs, as opposed to just a ton of SEOs (if you know what I mean). Yes, I even noticed changes in the search results and I really don't even look that carefully.
The way to submit your feedback is to use this form and make sure to mention the word "dewey" in the "Additional details" text area. Matt said you can also point out specific issues with the new index via "blog post, leave specifics on the Google webmaster help group, or whatever way you want to point out specific searches that look different to you." He also added that even if you don't get a reply, it is very likely your details will be reviewed by an engineer. Here is Matt's post:
Hey all, I asked a few people to look into this and they weren't seeing many large differences in rankings between these datacenters. The issue with discussing on this thread is that specific urls/queries aren't allowed. If anyone wants to mention a search where they see large-scale differences, feel free to send feedback to Google in the usual way. I'm going to pick a random-but-pretty-unique keyword so that I can look up reports. Let's use "dewey" as the word. So if you want to mention a search where you think the results are very different at one data center compared to other data centers, use the spam report form at http://www.google.com/contact/spamreport.html and make sure to include the word "dewey" in the "Additional details" text area. Or feel free to point out differences in other ways: do a blog post, leave specifics on the Google webmaster help group, or whatever way you want to point out specific searches that look different to you.
The usual rules of thumb apply: you probably won't get a personal reply, but I'll try to get someone to check out reports that get sent in. There shouldn't be much difference between data centers, so I'm curious to find out what queries people seem to be seeing different results on.
So maybe this Google update should be named the "Dewey" update? Why not?
Forum discussion at WebmasterWorld.