Is it coincidental that T-Mobile USA Chief Executive Robert Dotson resigned the same day Microsoft abruptly had key openings in its Entertainment and Devices division?

T-Mobile's announcement said Dotson (below) will "transition to new opportunities in 2011."

Meanwhile Microsoft is still trying to figure out how to reorganize the E&D group. One option would be to split the phone and mobile devices business into a separate unit, apart from the games business.

A standalone Microsoft phone business could be run by Andy Lees, senior vice president of the company's mobile business. He's a 20-year company veteran who previously led server and tools marketing.

Or perhaps the phone business will be led by a newcomer. Like Dotson, who has been Bellevue-based T-Mobile USA's chief executive since 2003.

Dotson is the most connected wireless guy on the market right now, he's in town and he's got the consumer savvy, industry respect and sense of urgency that Microsoft's phone business needs.

T-Mobile's business has had a tough go lately, but it's been scrappy and innovative. It has experimented with new calling and data plans, goosed its network to produce near 4G speeds and kept pace with the surging smartphone business by releasing a stream of leading edge devices, including the first handsets running Google's Android software.

Has anyone seen Steve Ballmer's Lincoln in Factoria today?