Just got an email from David Rees at BlueRail Trains giving an update on their new form factor.
For those that might not be following, BlueRail is the maker of the board and software behind the Bachmann EZ App, and allows direct control via your smart phone.http://www.bachmanntrains.com/home-usa/ez-app.php
Some have started to experiment with BlueRail in N scale - mostly to run the layout. But the ideal use is stuffed in a train and their original PCB and components were just too large for N and even many HO engines. But here is a look at the newest BT module to which they plan to migrate: http://bluerailtrains.com/img/BMD-350_Compare.jpg
No release date yet.
I'm no expert on this - only sat in on David's update presentation at a local NMRA event - but it seems a promising way to open up many doors, including improved interface for existing DCC decoders, "dead rail" (AKA control over a battery powered unit) and external sound.
Something to watch, for sure.