Microsoft's big decision: Who gets a free upgrade to Windows 10?

In December, Microsoft COO Kevin Turner said that the firm would reveal its Windows business model plans in early 2015. Details of that model have not been disclosed, but would certainly include how Microsoft figures to make money off Windows after it's begun giving away licenses to makers of phones, smaller-sized tablets and inexpensive personal computers.

As part of an explanation of monetization -- which Turner acknowledged requires "creative ways" -- Microsoft might also use the January event to discuss Windows 10's upgrade pricing.