With PyCharm 5.0 we finally got to select Google and NumPy Style Python Docstrings templates.
It is also mentioned in the whatsnew section for PyCharm 5.0.
How to change the Docstring Format:
File –> Settings –> Tools –> Python Integrated Tools
There you can choose from the available Docstrings formats:
Plain, Epytext, reStructuredText, NumPy, Google
As pointed out by jstol: for Mac users, this is under
PyCharm -> Preferences -> Tools -> Python Integrated Tools.