CPython is very focused on speed; and is already planning and working on adding a JIT in the near term. I would guess they will implement their own rather then

CPython is very focused on speed; and is already planning and working on adding a JIT in the near term. I would guess they will implement their own rather then merge Pyston but the end result for people using Python should be similar. The CPython team is (correctly) very concerned with code quality and the ease of maintenance. This favors starting with a very simple JIT; very aligned with the interpreter.