I've been doing some digging. I tried something but of course it didn't work, since I don't really know Python. But I think I'm on the right track.
In CvMainInterface you import CyInterface and create an instance of it(?). This class has the function (method?) getMousePos(), which returns POINT object. POINT has 2 attributes- int x and int y, which in this case will correspond to the location of the cursor. What I don't know is how to access those ints. If you create a CyInterface called screen_interface or whatever, then "mouse = screen_interface.getMousePos()" would create a POINT called mouse, right? But then what? mouse.x and mouse.y? POINT doesn't have any functions listed in the API, just those 2 ints.
FWIW, according to the online API, CyInterface will not be included in the SDK.