I'm not so sure the "next Ruby on Rails" necessarily prescribes a full stack framework like meteor. They have an impressive demo that showcases what you can do

I'm not so sure the "next Ruby on Rails" necessarily prescribes a full stack framework like meteor. They have an impressive demo that showcases what you can do with full stack javascript, but having spent a few years now in that full stack environment.. none of it is new. ie. all of this is out there, just not packaged together. IMO the next Rails is anti-Rails. It's more about building from the ground up than having all your decisions made for you. (meteor packages?? Fibers?? no thanks.)