Yes, Zap imports the Smart car. And you can theoretically buy one in Canada. But the problem is that there is not the necessary infastructure to support the vehicle in the USA. Where would you service the car? What about getting parts for it? More headaches than it is worth.
I seriously doubt MB-USA would bring Smart cars into the US in 2006 or 2007. Like I said, they officially stopped supporting the smartUSA efforts last year. Even if they bring that idea back on the drawing board, it would take a couple of years to get the necessary infastructure, training of the mechanics, marketing the car...etc.
BTW: I work for Mercedes Benz, USA corporate headquarters.
-Z-man.