The map control should have the ability to disable the spring animation separately for panning without disabling zoom animation.
This feature is implemented already for the WPF version of the RadMap control (you can use SpringAnimationsMode property). It seems quite difficult to implement the same for the Silverlight version. The difference between WPF and Silverlight is the MultiScaleImage control. In the WPF we use our own implementation of the MultiScaleImage , so we have a full control on its behavior. In the Silverlight we use standard control which does not provide similar functionality.