Thanks for the clarifications. I agree that the US will logically move up the J-curve to have a single connector on the car. I also feel that logically Europe would move along a Mennekes pathway. This will be fine since:
1. Very few cars will ever drive from North America to Europe
2. Major OEMs (even Tesla) make different versions of their cars for European and North American homologation (even different between US and Canada).
3. Electric and control systems will be likely identical (J1772 US and Mennekes single phase are, I guess J-DC an M-DC may adopt/extend CHAdeMO signalling and electrical standard) even though the connectors differ.
Then there is the question of 3-phase. It's a big deal that you can get nearly to the power of CHAdeMO DC (50kW) with a 3-phase EVSE. The former needs a very large piece of equipment that costs >>$10,000. The latter needs very little equipment (not really any more than a Tesla UMC) as it does no power conversion. This means that it could cost a few hundred dollars, certainly no more than 10% of the DC equipment. It fits really well with the way the grid really works (3-phase after all was pioneered by Nikola Tesla and won the battle a century plus ago). Therefore there is a great prospect for medium-fast (1 hour for 150 miles) charging to be implemented vey widely across Europe if the cars support 3-phase.
Can the cars support 3-phase charging cheaply? Well Renault clearly thinks so, as do the German car makers who back Mennekes. The electronics for inverter drive of 3-phase electric motors (Like the ones Tesla Motors uses) and especially for 3-phase regen to the battery must in principle be able to support 3-phase charging. (Note the Roadster can regen from its 3-phase motor about 40kW - that's about equivalent to 3-phase 63A charging though in the Roadster's case I know the connections were never designed to allow this, and fast charging with the Lithium Cobalt battery chemistry may not be sensible. These restrictions needn't be the case on ModelS or any newer car - and certainly if 100kW DC fast charge will be allowed then 43kW 3-phase must be fine for the battery.)
So I think why some people (me included) get worked up about this issue is:
1. The grid extends a 43kW service very easily in Europe (63A, 3-phase)
2. Electric cars that use 3-phase motors and do regen have hardware on board already that should easily re-purpose to use the 43kW for charging
3. Vendors who are developing their cars in Japan and US are ignoring this potential and forcing a model that requires expensive equipment to deliver roughly the same power (DC)
I don't know if in the long run any of this will matter. But it feels like we could accelerate faster in Europe if we agreed to use Mennekes style connectors; cars could accept 1- and 3-phase AC, and DC fast charge via these connectors; medium fast charge using 63A 3-phase was rolled out aggressively as it is low cost, and some DC in key locations.
NB this plan would may not be optimal for the US, given all the comments about 3-phase being scarce there, though I wonder if it's really scarce at the business and local distribution level.