There are already a few common standards (at least here in Europe.)
For public charging station almost every manufacturer uses the TYPE2 (MENNEKES) plug, the actual charger is built into the car. For fast-charging there's the CHADEMO standard (japanese) which a lot of electric cars use and the newer 'European' Combo-plug (an extension to the TYPE2 plug) that is currently in-use by the BMW i3.
In The Netherlands (where I live) a company called FastNed is building a fast-charging network on the highways, they offer TYPE2 (for cars not having fast-charging support,) COMBO, and CHADEMO and usually also have a conversion plug for Tesla cars so you can also charge them there. I hope part of this subsidy allows companies like them to get stations along the German highways as well.
For public charging station almost every manufacturer uses the TYPE2 (MENNEKES) plug, the actual charger is built into the car. For fast-charging there's the CHADEMO standard (japanese) which a lot of electric cars use and the newer 'European' Combo-plug (an extension to the TYPE2 plug) that is currently in-use by the BMW i3.
In The Netherlands (where I live) a company called FastNed is building a fast-charging network on the highways, they offer TYPE2 (for cars not having fast-charging support,) COMBO, and CHADEMO and usually also have a conversion plug for Tesla cars so you can also charge them there. I hope part of this subsidy allows companies like them to get stations along the German highways as well.