A MSFT tablet?
Mmm. Last year I would have said I doubt it. In my years at MSFT it was certainly billg's deeply-held conviction that the company doesn't compete with Win OEMs. Every temptation was firmly rejected.
Of course things can change, and in business few things are cast in stone.
I for one would be astonished if it were a tablet. That would signal a dramatic shift from a founding vision.
But an ARM machine with RT is sufficiently ring-fenced architecturally, and in terms of traditional IHV relationships is sufficiently out-of-field to just possibly not hurt too much.
Still, anything is possible. If there is a MSFT tablet, which would only be on ARM, it'll strengthen my own view (no inside info) that Win RT (ARM) is not a core platform, though it could be big volumewise. It might in fact be a good way of nudging the big IHVs to x86 Win8, thereby protecting the Wintel franchise (ie core) and keeping the non-Win cheapies to slash 'n bleed on Android.
And if it works even moderately well it'll drive Metro apps, which is great for WP8, and lays a good foundation for Win9 in late 2015, when corporates next upgrade.