Just parking this here so I don't lose it:

      YEvent.Capture(ymap, "onPan", function() { /* blah */ } );
      GEvent.addListener(gmap, "move", function() { /* blah */ } );
      mmap.AttachEvent("oncontinuouspan", function() { /* blah */ } );

Google v2, Yahoo v3, Microsoft v2

Map events seem to be custom messages for each API. I don't think they use the DOM events functions. That means it might be easier to do our own limited set than to wrap them.