I think Boomer23's point had substance. The Smart is intended as a city car and will never be anything else. It's a brick at highway speeds so its already short range will be even shorter in fast rush-hour freeway commutes, and while the electric motor eliminates the single biggest complaint about the car (the awful transmission in the ICE) and improves some other things, most of the shortcomings remain. The problem is that a short city car's raison d'etre is an ability to parallel park in spaces too short for other cars. If you're an apartment dweller who can charge near/at work during the day or who happens to be one of the lucky few who have public charging near their residence, well and good, but why would anyone who owns a home with a garage and can afford either opt for the Smart? The sole reason I can think of is that Smart will be the first EV to offer battery leasing with a capacity warranty in the U.S., so for people who are worried about long-term durability that may be the critical factor (and will also lower the MSRP). I feel all EV companies will have to offer this eventually to get the MSRPs down, the sooner the better. It also puts the onus on the car companies to be honest about their battery life in different conditions and price the battery lease accordingly; if they lie, they are the ones on the hook for an early replacement.
Until on-street public charging becomes widespread, the only reasonably-sized niche I see the SMART ED and similar city cars filling in the U.S. is for car-sharing services, for which they are near-ideal, and for take-out food delivery. I think Toyota made the right decision to restrict the Scion eQ to fleet sales for that reason. The 500e (and SparkEV) are a lot more car for the money than the Smart ED, even though they're not much bigger.