Coming very soon. Before the end of the 2nd quarter you will be able to create a free demo account online. If you'd like to discuss getting access sooner, it's possible but you'd need to contact our sales team. We have users trading on the system every day including from their macs, iPhones, and android devices.
I stopped caring personally. I just run Windows 8.1 in VMWare Fusion and just do everything from there via another desktop space. ctrl-right arrow and I'm in my trading VM. ctrl-left arrow and I'm back in OSX. No discernable performance concerns or otherwise. I do most of my trading from a 15" MacBook Pro - which just goes to show you don't need 10 monitors to trade.
I day trade using a Macbook pro with 3 external displays (even though Apple says it can only support 2, its not true). It runs W7. On OSX I'm have run 2 but I never gotten the drivers needed for my displaylink adapter. pretty sure it can be done as well