For those who don't mind some risks, this is how to get superuser rights
For people who feel fettered by the operating system of their Sony Tablet S, there is now a way to root the device and gain superuser rights.There are some applications that cannot be installed on Android tablets without superuser access, like custom ROM and certain apps used for backup.
The Sony Tablet S is like every other tablet in this regard, but where there is a will there is a way.
For those whose will is to access that superuser account status, a way has appeared to root the tablet.
There are some risks involved, but people who feel adventurous enough will need to put the Tablet S in USB debugging mode and unzip a certain archive, after which the batch file has to be run.
This post on the XDA Developers forum has the links to the files needed to use the exploit. Keep in mind, though, that the next official Android 4.x update (which Sony will have all tablets undergo automatically) might remove the root.