For us Thunderbolt users, it appears the Verizon Marketing/Sales department is in charge of the ICS update. I bought my phone on the first day the Thunderbolt was available and I'm eleigble for an upgrade in November. Most likely VZ want's to hold the ICS update long enough for owners to get fed up and buy a new phone, locking in new contracts.
Unfortunately for VZ, if I make that decision, I'm buying a phone outright, going month to month and most likely changing carriers.