Once I have the conversion command(s) documented in PEP 512 and I have created the "Python core" team on GitHub for all of the current Python core developers, I will migrate https://hg.python.org/devinabox
to make sure that everything works. After that has been verified as working I will then look at migrating https://hg.python.org/devguide/
(will take a little bit more effort for both to get the web builds updated, and peps requires getting the PEP editors on-board). The benchmarks repo might actually not get migrated as there is talk of starting that repo from scratch.
It's looking like we will stay on track to get at least one repository migrated by PyCon US!