Verizon's iPhone might look little different to the old model on the outside, but the guts share little in common. iFixit's ripped one up and reports significant differences beyond what's necessary to switch GSM and CDMA radios.
The location and design of the RF components--EMI (electromagnetic interference) shields, connector locations, even board layout--is changed. They redesigned the vibrator--a seemingly minor item, but it takes up a large amount of space inside the phone. My tester said that the "Verizon vibration was quieter, a little softer to feel, and made a better sound on the table." (No, I'm not making a 'That's what she said' joke.)The real news is that the chipset also supports both GSM and CDMA, suggesting "universal" models may be forthcoming. Verizon iPhone Teardown [iFixit]