I actually think tablets and similar are the way to go...
... because in iOS, applications are fairly well protected from each other. They have defined, hard limits on their functionality. Are they hackable? Yes. But it's a lot harder to get malware onto them, and much less likely. Windows 8, if you stick with the newfangled Metro/WinRT apps, is also the same way (something that they're taking from Windows Phone 7). When applications can't even open files outside of a few known, shared locations (like "Documents" and "Pictures") or their own local data, it means that I'd feel MUCH more comfortable handing one to a user and letting them download and install applications on their own. Is it still locked down? Yes, but the lockdown on iOS and Windows 8 feel much, much less intrusive that the traditional IT department approach of showing people what they could do, but then popping up "access denied" messages when they try it.
J.Ja