Updates to this story
While the Windows Phone 7 launch is still many months away a ROM image of a near-final release candidate has been leaked online.
The leaked version is build 18.104.22.16877 and WinSuperSite posted a number of pictures from it here.
Windows Phone 7 was first introduced at Mobile World Congress, where it was announced that the new mobile operating system would add in Xbox Live, the Zune music and video software, Office 2010, and all of the traditional things you would expect from a Windows-based OS.
It also touts a nifty feature of constantly updating live tiles. The idea is that you create a tile for a friend and it automatically updates with your friend's latest pictures and posts. There will apparently be no static icons, as everything is designed for “life in motion”.
There will be a dedicated hardware button for Bing to allow access to search results from anywhere on the phone. There will also be six different hubs on offer: People, Pictures, Games, Music + Video, Marketplace, and Office, all of which can be seen in the pictures below.