The link at the bottom left saying "Remove background image" puts it back to normal. Proof: http://skitch.com/petercooper/d8t8h/remove
(Update: Seems this doesn't work for everyone!)
(Update: Seems this doesn't work for everyone!)
EDIT: Actually, I selected a background, and then I was given the option to "Remove background image." Unfortunately, this just reset my background image to whatever Google had chosen for me.
If I select a "white" background, it doesn't give the old Google page -- it has translucent text with shadows. Looks super ugly. Very annoying.
Come on Google! People love you for your simplicity. That's one reason you broke away from Yahoo's then-dominance of search/startpages years ago.