Leaving it's smaller sibling, the Tablet P, behind, the Sony Tablet S was one of the first Honeycomb Android tablets to receive the Android 4.0 Ice Cream Sandwich update. Now the little brother has caught up. The Sony Tablet P will soon be able to partake in the tasty Ice Cream Sandwich goodness, as the update is now available for the tablet. You can grab it by tapping Settings > About tablet > System updates. It will only be available in select markets at first. They have even included some additional tweaks/features as well: "These include direct SD card access, "small apps" that can run in a window, and a re-vamped photo viewer."
Source: AndroidCentral