A few months ago the MBTA initiated a pilot program like this at Back Bay and Ruggles Station on the Orange line. They used big LCD monitors, like the ones I saw, to show passengers down to the minute Bus and Commuter Rail information, and also to show the position of trains on the Orange line. Another interesting fact about the screens and software used at Back Bay and Ruggles is that they cost the MBTA little to nothing. They made the monitors by using repurposed MBTA screens and all of the software costs were picked up by the company that made it.
Hopefully these monitors that I see popping up all over the Red Line will be just like the ones that the T is piloting on the Orange Line. It will be nice to finally know where the next train is and when it is going to arrive.
I will keep you all informed when I find out more!