Windows Phone 7 is the newest version of the Windows Phone operating system by Microsoft, which is planned for release by October 2010 according to some sources.
InformationWeek,Engadget and  Boy Genius Report are Already trying Windows Phone 7  ,
Windows 7 Phone  after the iPhone is expected to dominate the smartphone world the phone hasZune integration in it which makes Windows Phone 7 seamless

Windows Phone 7 User interface

The new interface, named "Metro" is very similar to that of the Zune HD
The Main screen "Start screen" is made up of tiles/squares, which by default are links to Phone's important features.Windows Phone 7 have a more friendly touchscreen UI than any previous Windows Mobile devices by using multitouch technology.The WP7 has pre  Integration with popular social networks, such as Twitter, Facebook, and Windows Live Windows Phone 7 will also be featuring  integration with Xbox Live, Zune, and Bing services.

Internet Browser

The browser is based on ie7 and ie8 tossed together which works much faster with less resources,the Windows Phone 7  browser will also supprot flash 10.1 the overall browsing experience will be much bettter than any previous Windows Mobile devices.

Camera

Windows Phone 7's minimum specs includes a 5mp camera to ensure that you're getting at decent shots no matter which device you choose.

Maps

Microsoft's Bing Maps implementation on Windows Phone 7 is great but not as featured as Google Maps on Android.

All windows 7 Phone must meet the minimum Hardware requirements

• ARM v7 "Cortex/Scorpion" or better processor
• DirectX9 rendering-capable GPU (well this is cool)
• 256MB of RAM with at least 8GB of Flash memory
• Accelerometer with compass, light, proximity sensor and Assisted GPS
• 5-megapixel camera or better with flash
• FM radio tuner
• 6 dedicated hardware buttons - back, Start, search, camera, power/sleep and Volume Up and Down
• Capacitive, 4-point multitouch screen