The new Google Instant is a big change.
One thing I have noticed is that you can not have Google Instant turned on and set your default setting to display more than 10 search results at one time. I have had mine set to 100 search results for as long as I can remember. The settings page will let you select 100, but when you turn on Instant, the page will only show 10.
Google Instant does not really impact most of my searches since I typically do not load the Google home page to search. I do most of my” googling” from the address bar within Chrome. And it will be interesting to see if they change this functionality.
It will also be interesting to see how it changes the search terms that people use. There are already a lot of conversations about Google Instant killing SEO. I certainly think it has the capability of changing SEO dramatically, but, as long as there are search engines, there will be ways to optimize for them.