As one of the major mobile operating system providers, Microsoft has established a successful business model by partnering with handset manufacturers and charging licensing fees for the use of its Windows Mobile system.

However, as companies like Google and Nokia are beginning to roll out new mobile phone systems free of charge, the business model of Microsoft's mobile business is coming under greater scrutiny.

Although the company said it will continue charging handset makers licensing fees for the use of its Windows Mobile system, speculation remains rife on how Microsoft will counter these new challenges. The latest version of the rumor is that Microsoft would release its own branded phone with Nvidia by next February.