Well, yes - it depends upon how you look at it.
Spriter works by having multiple image "parts", and for a given interval moving + rotating these + (z-order and a lot of other things). What is important is there is also a alpha value, and since all part images are only loaded one time, you could double your animations by copying each animation and setting the alpha value, so you have 2 sets: normal animations and fade out animations. And yes if the fadeout is longer than the animation then we have a problem ( we get a blinking animation instead ).
If we supported Spriter, we could probably make an global alpha value (+ a step value ) for each compound sprite, or for a group of sprites, this may in the user would only have to set the value once.
But again in the big picture you are right DarthMike, the easiest way is probably that the user handle it himself.
oh well, Im rambling again.
