The new smartphone OS from Microsoft is receiving praise for usability on par with iPhone and Android's experiences. But to reel consumers in, Microsoft will have to court app developers first.

Image by Michele Ficara Manganelli via Flickr

In an exploding market where an estimated $6.2 billion will be spent on 4.5 billion mobile apps this year alone, consumers find themselves essentially deluged with a large selection of smartphones powered by an increasing number of mobile operating systems from Apple (AAPL), Google (GOOG), RIM (RIMM), HP's Palm (HPQ) and now Microsoft (MSFT).

With Windows Phone 7-loaded devices just launched to the public, the software company that helped define the PC is hoping it can wipe its slate clean and start anew in mobile. Critics so far agree that the interface, an unorthodox unified tile-based menu system, is fluid and easy enough to navigate, but the bigger question remains: will mobile application developers back a new OS in a space dominated by Apple and Google? More