I don't know anything for sure about this image of a Hello Kitty-themed Darth Vader outfit (it's been suggested that it came from the San Diego Comic Con), though, honestly, what is there to say that the photo doesn't say for itself?
JPEG Link
(Thanks, Patrick!)
Update: Count Dookie sez, "That Sanrio Darth Vader is a quick Photoshop I did for a thread on The Dented Helmet, a Boba Fett prop-making site."