Gary, I don't see the eminent demise of the Arranger keyboard as long as there continues to be a strong European market for them, but I do see indications that their popularity and sales may be declining here in America. In fact, America probably doesn't even account for the majority of AK sales.
This could, however, produce a negative spin-off effect for American players though, in that styles and style production could/would become increasingly more European oriented (Schlagers and the like). This would lead to even more alienation by the younger players. Donny made some good points to support this; just because we may not want to hear them doesn't make them any less true.
But not to worry. Given the age of most of us, Arrangers will probably be around long after WE are gone.
"Faith means not wanting to know what is true." [Nietzsche]