Another Google experiment -- a few user have spotted a new search button on google.com and its search results pages. The new button which is inspired by Bing removes the old "I'm Feeling Lucky" button from the homepage.
It may be because, Google Instant makes the search button unnecessary most of the time.
Google's experiment highlights the header of the search results pages and uses gray/red icons and labels in the vertical navigation menu. Another change is that the "cached" and "similar" links are placed in the Instant Preview box, so they're more difficult to find.
All the new icons and images for this experiment are available in a CSS sprite.