In Pictures: Windows Phone 8 - killer new features...
Let's face it: Bing maps in Windows Phone 7 and 7.5 are a bit lackluster. They work okay for grabbing directions, but lack other features such as turn-by-turn navigation. In Windows Phone 8, Microsoft has opted to use Nokia's mapping software over its own, finally giving Windows Phone users turn-by-turn navigation and support for offline maps.
Developers will be able to use these advanced map APIs when building their apps too, so you can expect a slew of new apps that take advantage of Nokia's mapping technology.
In Pictures: Windows Phone 8 - killer new features in Microsoft's latest mobile OS