Earlier the HTC Vivid launched via AT&T got ICS update. It was the first smartphone from all leading brands, which managed to receive it. Other high-end devices, including the Rezound are also waiting for ICS update but it seems Verizon is the slowest in this regard.
As to the update, it’s an Android 4.0.3 Ice Cream Sandwich version with HTC Sense 3.6. It will bring all the goodies coming inside the OS but not all the changes will make users happy. For example, the same update is already pushed out for the Sensation 4G but it disables the tethering functionality on the phone.
Regardless of the fact you accept the changelog or not, it’s Android 4.0. So if you want to fall behind times, you should download it without hesitation.