For the first time I find myself captivated by a Microsoft mobile user interface. There is a lightness, a minimal quality and a logic to the interface design of Windows Phone 7 which has been absent from Microsoft’s previous offerings. It seems to mould content into an interface in itself, removing all of the iconography, menu layers and controls which have polluted previous mobile interfaces.

This principle of content as UI was a key part of our MEX Manifesto in 2008, when MEX Manifesto statement no. 1 read: “Icons are dead and the content itself is the new interface. By stripping away the confusion and clutter of traditional interface elements like menus and scroll bars we can put photos, music and video at the heart of the user experience.” The new Windows Phone interface embodies these principles.

Crucially, however, this OS stands out as a new benchmark for UI design – a genuinely compelling alternative to competitors. Of course, it is impossible to make a final judgment until the real experience can be tested on production hardware and it could be easily derailed by poor implementation of other experience elements – but, taken at face value, this looks promising.

The video above (excuse the low audio quality), shows a brief tour of the UI flow. It was demonstrated on a large touchscreen panel as Microsoft’s handset partners will not be delivering this on devices until late Q4 2010.

The messaging interface was particularly strong, using white space and typography techniques to create an uncluttered list where messages were clear and easy to navigate.

I also liked the concept of hubs, grouping together capabilities in individual UI areas rather than splitting everything into individual icons.

Microsoft needs to get this into the market as quickly as possible. It needs to supervise and check every minute detail of the implementation as it filters into production hardware. Above all, it must resist the temptation to ruin the elegant simplicity of what they’ve create by succumbing to the temptation to ‘enrich’ this blueprint with unnecessary additional tweaks.