I think it's more of a question of knowledge. Windows is more vulnerable etc. but at the same time with a virus scanner you know (hopefully) if there's something on there. It's not a guarantee by any means but there's a way to measure it. When was the last time you ran a check for a root kit on your Linux machine? Or on your tablet? It's obviously possible for such a thing to exist on the tablet but not likely. Still, there's no easy way to verify ...

To answer the question: I work at a university we have our wireless infrastructure cut off from the wired so I can use my tablet for PIM stuff and surf the web without worrying about the other machines on the network (File sharing is also not allowed). I'm still learning the ITT ropes so I expect to find more uses at work soon!