Well, it appears that shipping separate CDs for Mac and PC games is SOP (standard operating procedure) for GOD (the Gathering of Developers). This is unlike Myth and Myth 2, Bungie's last two releases, which both shipped as hybrid CDs.

Oni Central has posted that the SKU for a hybrid Oni release has been removed from the systems of online retailer Amazon.com and been replaced by two separate SKUs for PC and Mac versions.

While this raises speculation that the release might not be truly simultaneous, and might even make Oni's launch more expensive, it does allow publishers to better track sales to each platform. Also, Amazon.com is listing the price for Oni as $39.99.