As MP3Mike says, adapters will start becoming available to Ford & GM next month unless things get delayed.When non-Tesla EVs start being delivered with NACS connectors that will likely change the landscape. Tesla will have to expand superchargers to keep up with increased demand, but it will open up traveling to those non-Tesla EVs. Though the pre-NACS cars will be stuck in the EA ghetto until adapters are available.
I'm still in the middle with my opinion of opening the supercharger network up. One one hand, it means MUCH more expansion, and more locations for charging. On the other hand, it also means more vehicles using the stations, and more congestion.
Either way, I need to acquire a couple more FUSC Model S's & X's. My two current ones wont last forever and not looking forward to the day I need to start paying per charge ;-)