The fact that the N94 supports an A5 processor does not necessarily mean it will have an A5. It's quite possible that they contemplated multiple designs for the iPhone 5 including re-using the current design. Alternatively it may be possible that the iPhone 4"s" will have an A5 and cut costs elsewhere(plastic casing, less storage,). My guess is that the 5 will still have the design speculated by ThisismyNext.