BMW Already Working on i5
According to What Car, a source close to the management team said that BMW is already working on the new car. At the moment they are struggling to figure out what kind of car it should be and to whom it may be addressed.
Since the Tesla Model S is so popular in the US, the BMW alternative should be a direct competitor. That means it should come in the shape of a sedan. Another possibility would be to make it a crossover, since they are pretty popular in the States too.
Another important aspect to decide upon is whether the new car will be all-electric, if it will be using some sort of range extender or if they should go with a hybrid concept. Each has its advantages and disadvantages but at the moment it seems like the hybrid version is the favorite.
The best thing about the new car though is that it will be sticking to the traditional BMW values. It will be rear-wheel-drive and lightweight, using CFRP everywhere possible.