Last week, HTC released a detailed timeline of when ICS updates to various devices are expected to roll out. Hitting almost dead-center in the middle of its projected update window, users in various parts of Europe with unlocked Sensation XLs are now receiving the update. According to user reports, customers of UK's Three network are also receiving the update. Unfortunately, there's no word when other carriers will begin pushing the update.
The 197MB package brings Android 4.0.3 and Sense 3.6 to the handset. You can see if it's available on your device by heading into Settings > About phone > Software updates > Check now.