Here are some ‘How To….’ demo video on Windows Phone 7 . Watch it as you can switch to Windows Phone 7 as soon as it arrives -
Learn how to use Speech in Windows Phone 7 to make phone calls, search the web, and open apps.
Personalize Start -
Learn how to personalize Start on your Windows Phone 7 to make it unmistakably yours.
Learn about using Search on your Windows Phone 7 to find email, contacts, places, things on the web, and more.
And this video tells us about What you can do with Windows Phone 7 -