ATI announced its collaboration with Pixelux Entertainment, a company specialized in material physics simulation based on the Finite Element Method, to bring such rendering available for Microsoft Direct X11 AND Open CL. This is most likely a move to compete with the now well established PhysX engine used by NVIDIA, but only available on Windows.
The fact that ATI aims to offer it on both platform is most likely a sign of its involvement and probably a way for the company to demonstrate its interest in Mac hardware, software and OS. It could be the only or ATI to see its GPU back in MacBook Pro and Mac Pro. The goal is also to create a multi-platform standard to be used in games (making porting even easier). However, ATI/AMD will need support from Apple, and the company is currently trying to demonstrate to customers that the best Apple-tagged game platform is the iPod Touch/iPhone... of course they also use Open CL... Will Apple (in fact Steve Jobs) finally decide that games can be one way of using a computer, including Macs?