Tablet Operating Systems

So Apple now has an iPad tabled based on their mobile phone OS. Google seem likely to announce a series of tablets based on their Android mobile phone OS shortly.

I wonder how long it will be before Microsoft announce a tablet based on their phone OS rather than their desktop OS? As they're currently changing the name of their phone OS from Windows Mobile to Windows Phone I wonder what they'll end up calling it if they release a tablet version?

Surely Windows Mobile is the better name - doh!