To manually initiate the download, head over to your "Settings" app, press "About Phone" then "HTC Software Updates" and finally follow the instructions to download the update.
T-Mobile will allow you to download via Wi-Fi or 3G/4G.
Full feature update (via AandM):
Android 4.0 (Ice Cream Sandwich)
Sense 3.6
System bar enhancements to easily view recent apps.
Re-sizeable widgets
Lock screen actions including pull down notifications and adjust volume while device is locked
Data usage controls
Face Unlock
Home screen folders
Improved battery life
Written by: Andre Yoskowitz @ 20 May 2012 12:28