READ the Specs, Motion is 100% compatible with AE Plugins. So all your investments in plugins is secure. This is an AE Killer. And, by the way, Apple's software frameworks practically have everything you need already developed to quickly put together a Photoshop type App (same goes for MS Office). Apple needs to give users a reason to buy an OS X PC over a Windows PC, Adobe has maintained a common codebase based on the limited Windows API's and then ported their code to OS X.
Agreed Stingerman. I posted that before noticing the plugin support in AE after reading the pdf for Motion. Motion may be the best opportunity to ensure that AE stays on the platform. Adobe must know that Motion could quite easily become Motion Pro with all the "missing" features.
Shake is now $3k for the Mac and 5K or Linux and Irix. Apple is positioning themselves quite nicely.