There are some reports via Google Webmaster Help that some webmasters are noticing huge drops in referrals from Google since the Google Instant feature came out.
We all know that Google Instant has no impact on the ranking of search results on the Google search result page. But Google Instant does influence the types of queries people type in. So it may change how people search for buying, researching or navigating to web sites. The search query may have an impact on some sites. But are you impacted positively or negatively?
When Google launched their last search user interface redesign in May, 43% said their traffic was down since the update. But it was hard to pinpoint since the MayDay update happened just about the same time. Now we really don't have a major algorithmic update, so it may be easier to isolate the cause of a traffic drop from Google.
Please look at your traffic from Google, compare September 8 to September 13th to the previous week and see if your Google organic referrals changed. Then take this poll:
Now have your friends take this poll.
Personally, I checked several sites and none of my referrals are down, some are actually up a lot.
Forum discussion at Google Webmaster Help.