From the Motion 2 Late Breaking News PDF on Apple’s site:
(sorry for the formatting)
Adobe After Effects Integration You can import a Motion project directly into an After Effects project, preserving its quality without intermediate rendering of QuickTime movies or image sequences. Because After Effects interprets the Motion project as a movie, any operation that can be applied to a QuickTime movie can be applied to a Motion project. Once a Motion project is opened in After Effects, you can invoke the Edit Original command from the After Effects timeline to launch Motion and modify a project in Motion. Once the project is modified and saved in Motion, it is automatically updated in After Effects. Opening Motion projects in After Effects is certified only for After Effects 6.5, and has not been tested with other versions of After Effects. Motion must be installed on the same computer in order to view, edit, and render Motion projects from After Effects. To use a Motion project in After Effects: 1 In After Effects, choose File > Import > File. 2 In the Import File dialog, do the following: