Sorry for the very late response. It's holiday time :)
Although managing Windows machines from Pash would be a very good feature, there are no plans for WinRM support. It should basically be possible by using openwsman.
But it would clearly take some effort to get this working.
At the moment, resources for Pash development are low, so this won't be realized by the current team in the near future I guess.
However, if you are willing to do something at this site, feel free to start! I will do my best to support you with any questions.
Stefan