The Business Legacy
Win8/8.1 - mostly consumers will probably be well advised to do the free upgrade. Win7 - consumers with recent hardware might find it a good move too with '7' support ending within its lifetime.
Guess Microsoft are betting nearly all its Win7 business users will be unable to take advantage of the free upgrade. 12 months is just too short for any significant operation to evaluate, decide, test and deploy a new operating system. They will just hang on grimly until 2020 when it will, hopefully, be someone else's problem.