After many users complained that the new persistent sidebar from Google Search is distracting and takes away too much space, Google tests a new version of the sidebar that no longer includes icons. I don't think the icons were very helpful and removing them is a simple way to make the sidebar less annoying.
Here's the original layout:
Those who used the page http://www.google.com/webhp?hl=all to access the old interface probably noticed that Google redirected it to the new interface. You can still use the Hacker interface, the Linux-flavored interface, but the best thing to do is to try the new interface and learn about the tools and filters that could really improve your results. I constantly use the "updates" filter to search Twitter, the "discussions" filter to restrict the result to forums and the "past 24 hours/past week/past month" options to find recently updated pages.