A white background certainly lets the eye find the focal point.
(Go on, press it)
Herve Tullet (translated by Christopher Franceschelli)
Published in March 2011 by Chronicle Books
Here the title stands out. Check out the hardcover version which is much darker.
by Christine Johnson (Simon Pulse 2011)
The Trouble With Dilly hangs festive decorations onto the clean white background.
by Rachna Gilmore (HarperCollins, 2009)
White covers have been around for a long time. HarperCollins published Where the Sidewalk Ends in 1974 and kept the white for Every Thing On It (2011).
Ok, one more before I head out into the white stuff.