While the Windows 8 developer preview (available following the BUILD 2011 conference) is meant for developers, it confirms one fact-- Microsoft designed the latest Windows update for tablet use.
That's before mentioning the 5000 BUILD attendees who got free Windows 8 Samsung tablets, in an obvious gesture against Apple.
Confirmation comes as soon as one loads the OS-- a Windows Phone-style "lock screen" greets the user, who has to drag an image upwards to reveal a login prompt. A clumsy gesture for mouse users, but natural for touch-based use.
Then there's the Metro UI, the tile-based system looking like Windows Phone for tablets (users can still switch to a "desktop" option providing the more familiar Start Menu).