A few more tidbits from an email Brandon sent me late last night:
1) The input connector will probably mount where the frame-mounted Zero J1772 connector mounts, with modular connectors for J1772, 14-50 and hopefully CCS and CHAdeMO to follow soon. It sounds like details are being hammered out even as we speak.
2) The stock charger can remain in place, and probably be used concurrently if there are outlets available, to provide another ~12 amps. Brandon's thinking that many people might want to get rid of the 10 pounds of weight the stock charger represents, but mine will stay in place, both for backup purposes and as my daily overnight charging option. He says the "supercharger" weighs about 20 pounds, so it'll be considerably less added weight compared to the power tank. It'll be interesting to see how they make it weathertight and yet allow some airflow to keep it cool.
3) J1772, CCS and CHAdeMO all have communications protocols, so on those interfaces, the charger will automatically dial its current consumption back to avoid overloading the charging station. 14-50 probably won't need to throttle back.
I don't know about anybody else, but I'm incredibly excited. This is a complete game-changer for me -- I can visit my folks 90 freeway miles from me, I can head out to Palm Springs from where I live near San Diego, I can go on longer club rides. Now if Vetter will just heal up and get some fairings made, we'll be set!