May have already been said...and this is coming from someone who had the white iPhone 3Gs (now an iPhone 4) and a white iMac and used to have a white MacBook (Sold)
I've finally outgrown the white. For the longest time, I liked the difference of the the Apple white as opposed to the corporate Funeral black and the pall bearer gray of the HP's, Dells, IBM's, etc., of this world. But now I have sort of cottoned to the aluminum look of the current iMacs, MBA's, etc.
PS. I personally don't think Apple will change the design of the iPhone 4 until late next year...the CDMA version will be exactly the same as the current iPhone 4! Think of the negative press if they made any changes! And law suits, btw!