Seriously? What is the point of limiting yourself to one OS and then gripping about some app X not running on your flavor. Get a VM and buy a copy of Windows; problem solved. I have 4 OSes running on my laptop three of which are running under a VM. With the unity mode I don't normally even see the seams. I've got Snow Leopard, Windows 7, Ubuntu and Redhat. Actually I have 5 OSes but I don't use my Windows 8 pre-release which might have expired by now.
I am eagerly anticipating tools like this maturing to a level where really serious development can take place. I mean, I did a good bit of development in Flash and Flex but things really didn't take off for me until there were really powerful editing tools that went beyond dropping a few things on a canvas and tying them together with code. This tool but at a Unity 3D level of editing would super nice.