Most likely, OneGet won't replace pip/PyPI, any more than apt or yum does; but it may be worth having Python itself available that way. That might simply mean having someone package up Python and put it on an appropriate server, or maybe python.org could end up hosting a repo.
Python is already available in Chocolatey:
Given that OneGet intends to support Chocolatey as a repository, it might just work already. All python.org would have to guarantee is stable URLs for the Python msi files.