I understand Laurent's hesitation. It isn't as cut and dry as it may seem.
Sure Rect might seem strange in the Graphics module. But really, when you think about it, is it any less strange than the System module? What does Rect have to do with the system? At least in the Graphics module it has applications.
To me, the real question is, how are these modules defined? I get the impression that people here have the idea that the System module is sort of like a catch-all for the classes that don't fit anywhere else. But is that really the intent?
Perhaps a solution here is to introduce another module for one-off classes that don't fit anywhere else, like the Vectors, Rect, etc. But that's probably more trouble than it's worth.