Re: Appeal to teenagers, dual screen, low spec machines
If WinRT on a tablet is fundamentally like iOS on an iPad, then it's not appropriate for work. Let me expand...
In my daily use with an iPad over the last two and a half years, including taking it as my only device on holiday, I've found it to be invaluable as a communications device. It's great for emails, simple browsing, consulting the calendar, etc.
However, due to it's single-task non-windowed model, it's completely useless at more complex work such as writing an email whilst browsing whilst quoting from a document whilst running a web app whilst checking on other emails, etc. You know, the normal day-to-day business things that people juggle around. Compare that with OSX/Windows where multi-tasking is standard.
The key challenge is that running "Windows" on a tablet, a-la those keyboard/mouseless devices from years ago was an utterly horrible user experience, not least because all the benefits of a iPod-style tablet is missing (zero on time, finger-optimised UI, long battery life, ultra light weight, etc.).