In Pictures: Windows Phone 8 - killer new features...
A New Start Screen
One of the biggest changes coming to Windows Phone is the new start screen. Whereas Live Tiles on the current Windows Phone 7 start screen are more or less the same size, the start screen in Windows Phone 8 allows you to resize tiles based on importance. Care a lot about email? You can stretch out the email title to make it prominent. This new start screen looks great, and it was by far one of the cooler things Microsoft showed at the developer summit.
Current Windows Phone 7 owners will not be able to upgrade to Windows Phone 8, but they will be able to take advantage of this new start screen thanks to the upcoming Windows Phone 7.8 update.
In Pictures: Windows Phone 8 - killer new features in Microsoft's latest mobile OS