http://9to5mac.com/2012/04/14/apple-store-genius-bars-told-to-replace-select-white-iphone-4-models-with-4s-due-to-constraints/#more-160590 "Due to atypical inventory shortages of white 16GB iPhone 4 replacement units, 16GB white iPhone 4 customers seeking hardware replacements at Apple Store Genius Bars may get a free upgrade to the newer iPhone 4S. According to multiple sources, Apple has notified Apple Store Genius Bars that inventory of white iPhone 4 16GB replacements units is heavily constrained, and until further notice, stores lacking white iPhone 4 16GB replacements units should upgrade customers seeking a replacement phone to an iPhone 4S. This iPhone 4S would be a refurbished white iPhone 4S 16GB. This situation will not affect all customers and Apple Stores, but it seems like many white iPhone 4 16GB owners seeking hardware replacements may get Siri, an A5 chip, and an eight megapixel camera out of their next Genius Bar appointment. Sources specifically said that the issue pertains to Apple Stores in the United States and Canada, but the sources did not mention other countries or regions."