Forgive me if this has been answered already but searching for answers only brought up discussions regarding the iPhone 4 case. I'm a Sprint customer and pre-ordered the iPhone 4S. I was wondering if the cases for the iPhone 4s are universal in that they're all the same for ATT, Verizon and Sprint. I've been browsing these forums for a case for the iphone 4S and wanted to know whether there were any differences. From what I've read, the cases for the iPhone 4 were different for ATT and Verizon and I think also for the white iPhone 4 due to different locations for the proximity sensor or something. Thanks in advance.