Comment 5 for bug 554984

This is a user preference and not something that everyone would want by default. It can have an undesirable effect when you actually need to drag something with your middle button pressed (for instance dragging a folder in nautilus). I'm leaving this open, but my opinion is that it should be user configurable in the DE, and gpointing-device-settings does that, though input device configuration should be provided by the DE itself.