1) Embrace: Create PowerShell for linux, open source
2) Extend: Lure new users, add features that make linux life easier in PowerShell, take advantage of the existing linux desktop and mobile markets to supplement the failed phone market and extend the desktop market all while making it easier for developers to publish on both OSes.
3) Extinguish: a) Sometime around 2 major upgrade cycles from now, end support for all linux compatibility but provide tools to port what you need into Windows environment. Ignore the weeping and gnashing of teeth from developers who are forced to pony up to keep their tools current.
-OR- b) Gradually assimilate the best parts of Linux into Windows then slowly take over the community until essentially everyone is running some sort of Microsoft developed hybrid with just enough closed source parts to make the open source alternatives not financially feasible for businesses to invest developer time into. Adopt the freemium model where Linux and Android are free and Windows is the paid part that businesses will shell out for.