On the AE-List, Lloyd Alvarez noted a tool to view embedded metadata in files, including projects embedded by After Effects into QuickTime renders.
It's pretty cool if you want to root around inside files -- and there's a lot going on in there.
The previous link gives you a .TAR archive, but there's an additional link to the Windows .EXE and Mac .DMG for ExifTool, "a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in image, audio and video files."
Update: according to Phil Spitler on the AE-List,"it looks like the AE project details are not stored as EXIF data." Dave Simons added, "... IIRC the data is stored in a QT user data blob with the tag 'Cr8r'. Not sure if there are any scripting languages that access QT user data. Related question: does anyone use the Embed Project Link & Copy option (i.e., embed the entire project in the movie)? Or just the Project Link?"