Ruben spotted even more Google tests in the search results. He posted images of these new sets of tests in the Google Blogoscoped Forums.
Here you have Google testing the positioning of the thumbnail image for both video and news results.
On the video results, you have Google testing the thumbnail on the left and right side of the result, you have them testing various sizes and different styled play buttons.
On the news results, you have Google testing the position of the image for the news item.
Forum discussion at Google Blogoscoped Forums.