I agree Southwest is a possibility. Since they have many flights of a few hundred miles or less than 1000 miles, I wonder what the percent of their flights would justify having an eVU on board.

I'm not sure of the mileage that suggests an IFE would be appropriate for customer rental.  

With the crude price at $70-80 dollars, the airlines must be looking for added ways to increase their per flight income. An eVU would help a little, hopefully they will consider this from the customers viewpoint.