This still leaves the situation of carriers only accepting certified SIM's upon their network. Also this is very much like being able to port your phone number

This still leaves the situation of carriers only accepting certified SIM's upon their network. Also this is very much like being able to port your phone number across networks and with that you will still have provisioning hoops to jump thru as it is not that instant. Now a SIM you could provision with more than one carrier, that would be handy, though that is already available with dual SIM phones. So I'm not entirly sure this is as big a deal as being made out. After all a SIM costs nothing, yet the phone that is locked to a network, now that is another issue. More important to have the ability to purchase a unlocked phone than a unlocked SIM that you can just swap out. Though this could lead to the Apple idea of having the SIM built into the phone and recreate CDMA for GSM, after a fashion.