I personally think that the U.S. is not ready for a complete electric car (solely electric). They may come up with a few models, but overall, we do not yet have the infrastructure for charging the vehicles. They may continue to rise in popularity as a commuter car, but will not completely take over the market.
China may be more aggressive at pushing these vehicles, and possibly even installing the charging infrastructure. They have a serious pollution problem (more so than even us), and they appear to be very driven, toward electric cars. Ultimately, Tesla (and other competitors) may find that the lions share of their market lies in Asia.