Step 2 prepares the update for the carrier's certification lab by testing its quality and stability. Bugs are removed in this process. After as much as a 2 month preparation cycle, the carrier's lab tests the update which could take 1 to 3 months. At this point in the process, Motorola conducts tests with customers to make sure that the update is working right. This is the so-called "soak test".
The final step is to release the update. According to Motorola, deciding which phones will receive it is based on factors like the capabilities of the hardware and the device, the software support for the chipset on the phone and the ability to support "the Motorola value add software".
Adding it all up, it comes out to about 4 to 6 months to complete the process. Google has released the source code for Ice Cream Sandwich and Motorola is checking it out. The devices that will definitely get Android 4.0 at the moment are the Motorola DROID RAZR, the Motorola DROID BIONIC, and the Motorola XOOM (including Family Edition). Have a Motorola phone that you are hoping will be running on the ICS update? Motorola hopes to announce the other devices that will be updated sometime next month.