I think battery/RC will take off once someone starts installing the system in locomotives from the factory. I think it would be really cool if someone would come up with a hybrid system where you can run on power from the rails and use the battery to go over switches and complicated track work, then you go to a friends house that has a layout with no track power and you flip a switch to go to full battery power. This way they can sell locomotives to guys that run battery/RC and guys that run track power.
One problem I see if say MTH installs company A’s battery/RC system in their locomotives and Lionel goes with company B’s battery/RC system in their locomotives then the user will need two controllers to operate both locomotives.