Many of the old, historic mansions on Miami Beach and elsewhere in Miami Dade County have been converted for commercial purposes. Some, such as Deering Estates and Vizcaya are now part museum, part event locations (upscale parties, weddings, etc), others such as Merrick house are simply museums, and others, like the current state of the Vercace Mansion are commercial. There are a number of insanely huge and opulent homes on Miami Beach and on the Islands, plus in a few other neighborhoods in the county that are still in use as single family homes. If I'm reading the listing correctly, it could remain in commercial use, but it is technically zoned as "single family". Personally, I'd love to see it turned into a public access museum like Vizcaya, since Miami isn't exactly known for preserving its history very well.
Sorry for the hijack!