If the 4G sim card is anything like their 3G Global sim card, it's not going to be like AT&T's Sim card where it stores address/contact information. Of course this being new tech, you'll have to wait to see. I can't imagine Verizon following AT&T's lead and storing contact information on the Sim. It just probably tells the 4G towers whether or not your phone is provisioned for 4G.
Actually Verizon LTE will be using a little bit different SIM cards from the current 3G SIM. They will be UICC SIM cards.
Here is an excerpt, credit goes to willzzz:
The SIM card is required for ALL 4G devices even when in CDMA only mode. See this:
http://en.wikipedia.org/wiki/Removab...dentity_Module
VZ is adopting SIM-technology for all 4G and beyond future releases for ease of use because you can switch your account profile from phone to phone as long as it's a VZW 4G device and it will seamlessly work. No more calling support, you just swap the SIM card. No more *228 except for PRL updates but that in theory should be done automatically too in the future.
If you really want to know what's in the Thunderbolt here you go:
UICC - Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/CDMA_Su...dentify_Module
The Verizon 4G LTE SIM cards have 3 components in them (3 modules that are transparent to the end-user):
1. CSIM: Authentication to the CDMA 1X voice/data and CDMA EvDO rA data 3G network.
2. USIM/ISIM/USAT/ISIM: USIM is used for LTE/GSM/UMTS/HSPA data authentication. The last 3 are for roaming.
1. USIM is also used for native direct Verizon SIM card roaming when abroad (outside of the US) as long as the device hardware has the processing (baseband) and antennas to have the overseas bands.
2. ISIM is used for IMS (IP Multimedia Subsystem) authentication. Basically in the future Verizon wants to do VoLTE and move voice into IP (VoIP). This allows for ALL-IP simplified network management. Also device management and stuff that makes the device automatically work when it connects to ANY network in the world /w VZW roaming agreement (aka SMS/MMS).
3. USAT: Application toolkit for the SIM card. If you're not a developer forget about it.
4. ISIM (Intelligent SIM): One of the functions/applications is remote modular address book movement. (Only up to 256K). So if your address book contains up to 256K you can move it onto the SIM card and move your address book seamlessly transparently to the end user between any VZW device. There are other functions that only the engineer would understand.
"The application has been ported to the UICC (Universal Integrated Circuit Card), so that a card with CSIM, SIM, and USIM can operate with all cellular networks worldwide."