@cheong: The WindowsRT restrictions have nothing to do with ARM being inherently more secure than x86. They are due to the OS having a more restrictive policy. It is entirely possible to run Java on ARM. It's also possible to buffer overflow ARM devices, and to exploit sandbox logic bugs such as those in Java and .NET.
Running on ARM doesn't afford you protection. Running on RT does.
I'm not saying it's more secure. I'm saying it's not actively targeted (yet).
At least we can ignore the already swamping x86 targeted virus/trojans in the wild.
While it's possible to run Java on ARM, Oracle still has no plan to release JRE for WinRT yet.
It's possible to buffer overflow ARM devices, but as long as their shell code won't run on ARM, all you can have is Denial Of Service type of damage and your machine is not pwned.
This makes WinRT machines desirable for loosely monitored remote site environment.
Of course the other option would be to run the business on webserver, and install diskless workstation with DVDROM only, and use a LiveCD to browse the business web applications. In that way whenever the machine is "infected", a single reboot can get rid of them. Yet I don't see a lot of these chainstore I.T. comfortable with Linux systems.