Sure; I've mentored Robin throughout the summer with this, and this is his GSoC project.

As for the specific change: this is primarily to support PEP 3121, and allowing multiple interpreters to use a module without fear of global variables being shared across interpreters. 

In the current implementation, the Random type would be shared across all interpreters, with the change, each interpreter gets its own copy of the Random type. For that, the type needs to become a heap type, which is best done with the PEP 384 API (even though ABI stability is irrelevant for the random module).