Microsoft (MSFT) plans to continue charging makers of cellular phones an estimated $8 to $15 licensing fee for use of its Windows Mobile operating system. The software giant is under increasing pressure from Apple's (AAPL) iPhone Google (GOOG) G1 and Nokia (NOK) which recently purchased Symbian and plans to develop an open source or royalty-free software package and make it available to other makers of smartphones. "We are doing well " Steve Ballmer Microsoft's chief executive officer told Reuters. "We believe in the value of what we are d뻈鉗㸌 ...