That said, do bear in mind that according to the mark along the bottom of this part, we're apparently looking at an "EVT1" (Engineering Verification Test) piece from March 3rd 2011 (making it about three months older than the white N94 back covers that made the rounds last week, assuming they're legit).
ENGADGET: iPhone N94 prototype's front assembly leaked, set to be an iPhone 4S?