Really?
Take a closer look. There may not be a SIM slot, but there is a SIM card. On the Sprint iPhone 4, which has no SIM slot, the SIM card is soldered to the logicboard inside the phone. The Verizon iPhone 4 has the Dual CDMA/GSM Qualcomm MDM600 chip. Apple on purpose locked out the GSM part and of course, there is no SIM slot. So, technically, yes, the Verizon iPhone does not have a SIM card, but it DOES have the potential (albeit very difficult) to be a world phone.
You are correct that the Verizon 4s is locked to Verizon.