Several observations from me regarding the superchargers:
1) I think the paired stalls that split power will remain. This saves costs for Tesla by not needing that many power supplies, which I assume are much more expensive than the units at each individual stall (which are just cables and holders for a cable). Shared power supplies make sense because most of the time, the superchargers are not at capacity, and having independent power for each stall is a waste in most cases. Even if both stalls in a pair are occupied, it is likely that one might not be charging at max rate (e.g. close to completion), which would leave excess capacity for the other stall. Perhaps Tesla can make this configurable, and for stations with high occupancy at important junctions, use independent power for each stall.
2) I do believe that it is possible for Tesla to use CCS, or some other type of new connector. It'll be inconvenient, and may be costly, but probably not overly so. In Europe, they may even be forced to do so if industry/government forces standardization on CCS. Why? This is exactly what Tesla has done in China over the past few months: Issued all existing owners adapters, converted ALL superchargers in the country to the GB plugs, and shipped new cars with new connectors only.
Those that argue that Tesla has no need for this because of how much larger the SC network is, is being very short-sighted. In the long run, a single network will never be able to exceed that of the rest of the industry combined. And Tesla would be doing its owners an injustice if Tesla forces its cars to be incompatible. Look at Android vs iOS market share, or look at the availability of charging stations in China. (I'm referring to quantity, not quality here.)
3) Tesla will almost certainly up the voltage in order to double the power. If just doubling the current, then resistance losses would quadruple, very inefficient.
4) Faster supercharging would most likely accompany the next generation of high capacity batteries (e.g. Roadster with 200kWh). Due to the larger batteries that need filling up, total charging time would not decrease. However, you can probably expect to need to charge less often with larger batteries. New cars almost certainly won't have free supercharging due to the higher costs involved in charging larger batteries.
5) Probably not much new for old cars. Charging speeds would not increase (except maybe greater power when both stalls in a pair are occupied due to more headroom available) and charging times would not decrease. Tesla will have to ensure compatibility for old cars somehow, either through the same connector, a second connector, or some kind of adapter.
