Freedman also said that Nvidia is investing additional resources to support other mobile operating systems, which could include Apple's OS X used in the iPhone.

But another analyst said it would be foolish for Microsoft to launch its own smartphone. The company may be thinking of adding cellular capabilities to the Zune, he said, but such a move could backfire on them, said Jack Gold, principal analyst at J. Gold Associates.

"They haven't set the world on fire with Zune. Why do they think they are going to do any better if they put a phone on it?" he said.

Apple had instant success with its iPhone, but Microsoft doesn't have the same type of allure among consumers that Apple has. Windows Mobile has a stronger following among businesses, with its support for applications like Microsoft Exchange and extensions for business productivity applications, Gold said.

Windows Mobile is already licensed by top smartphone makers like Samsung, Motorola and HTC, so there's no reason for Microsoft to enter the consumer market, he said. Making a smartphone of its own could also antagonize Microsoft's licensees, who could easily switch to one of several free, Linux-based platforms such as LiMo or Android, analysts said.