From the last paragraph of that article:
Later, look for a convertible with a carbon-fiber retractable hardtop, a sedan, a wagon, and a lightweight coupe. The latter two probably won't be sold in the United States, but we haven't given up hope yet. Whatever the body style, we're dying to get our hands on one.
My next car (2 to 3 years from now) is going probably going to be a wagon, but I'm not going to hold my breath for the M3 wagon. Shame really.