HTC was quick to announce their devices that would see the update, but never detailed an actual time frame for most. If you have the HTC Rezound the day is today because Android 4.0 ICS with Sense UI 3.6 has just leaked in an official build. The leak is not the final version but should offer a pretty good idea of what to expect to those interested in installing the new build.
In order to flash the update (including the new radios) to your HTC Rezound, you will need to have a completely stock device. Those who have a custom recovery or have used the HTC bootloader unlock tool will need to flash a modified build of the leak which is already rooted.
Source: Android Police