Yes, it's scriptable. Assuming the operator has placed the image, you'd duplicate the frame. Then in each you'd use the "graphic layer options" property of the image to get a reference to the graphic layer option, which has graphic layers as elements. You can then change the "current visibility" property of the layers.
So something like this (untested):
tell application "Adobe InDesign CS4"
set theFrame to item 1 of selection
set newFrame to duplicate theFrame
set glOptions to graphic layer options of image 1 of theFrame
set current visibility of graphic layer 2 of glOptions to false
set glOptions to graphic layer options of image 1 of newFrame
set current visibility of graphic layer 1 of glOptions to false
Shane, you are a total star! I was unable to translate anything in the InDesign Scripting library into script that would run, and gave up and spent most of yesterday struggling to put it all together in QuickKeys, with limited success...
Your script works perfectly. I have a couple of extra bits to add (back image must be set to blend mode multiply) but I've worked that out by myself and the script is going to start changing lives today.
Several large, cold lagers are yours if our paths ever cross!