I think there should be a sensor boxcar that would beam to the sensor track, that would be something that could be incorporated in any consist and offer the same functionality to older locomotives. I'd like to see it be programmable in some fashion so that you could own a couple of them and use them in various configurations, you wouldn't need that many. Perhaps a USB connection to your computer to program the characteristics of the consist it was going to run in?
If the protocol for the transmission from the locomotive was available, this could even be a 3rd party project, it would be a great product.