According to canonrumors.com Sigma Corporation of America has announced the MSRP and availability of its 70mm F2.8 Macro Art lens in a press release today. According to that the three variants of the lens will not be made available at the same time. The version for the Canon EF mount will arrive first at the end of May, the one for the Sigma SA mount will be made available sometime in June and the Sony E mount version will start shipping at a later date.
There won’t be a version for the Nikon F mount. Why that is, is currently unknown. In several photography forums users are speculating that it could have something to do with focus by wire, or in other word electronical instead of mechanical manual focus implementation. Supposedly not a single Nikon DSLR supports focus by wire. As a reminder, Nikon is a rather conservative manufacturer, who was one of the last to renounce mechanical aperture control.
The MSRP is $569.00, which is admittedly a bit more than I had hoped. Since the press release was released by Sigma CoA, it is not yet known how much the lens will cost in this part of the world. A price of more than 600 euro seems to be all but certain.