These guys are hanging in there. I've written before about the difficulty of pushing any engineering product that runs on the Mac, due to Apple's not taking the engineering and architectural markets seriously. At Ilexsoft's last major release, I complimented the product, but hoped it could survive.
Well, the market has surprised me. I don't know how they are doing in the States, but this Italian company is being sustained, with a very-low-cost, full-featured product, in a space already occupied by the likes of Nemetschek, Engineered Software, and--on the high end--Graphisoft.
This latest version is quite impressive. Personally, I think the Mac is a viable choice for architects; and from an IT and total cost of ownership point of view, it has a lot going for it.