This is nice, because I hate all the spam sites that take your Google query and put it in the text of the page somewhere. Before long, the spam page attracts hits for that query because the page now contains that exact text. By hiding your search from the site that you're visiting, they can't do this anymore.

I've always disabled cross-site referers because it's none of anyone's business how I got to their site. This seems to be the way the winds are blowing now.