It's still early but it looks like there's a big update happening to Google results. First signs of it were early this morning and it's now rolling out to the various servers around afternoon evening East Coast time. Right now it looks like it's localized to google.com so it remains to be seen what the long term effect of these changes are going to be when things settle out and if the changes will roll out to the international servers as well.In terms of profile, it looks like "big" sites with many pages that get long tail search traffic are seeing a drop in SERPs/traffic. No clear profile is coming up on what they're being replaced with.