This new test, as you can see from the image in this post, has the icons removed from the search options on the left. The icons that were originally introduced in 2009 with the Jazz user interface is now being removed for some users.
This test seems to be going on with the new Google top bar test at the same time. I personally do not see it but Ruben posted a screen shot.
The icons kind of grew on me, especially since the colorful icons came to the mobile search interface.
Forum discussion at Google Blogoscoped Forums.