Ahh, I see! In that case, yes it does make sense because a plugin module (the .aip file) is implemented as a bundle on the Mac, which is actually a special kind of folder - Right click on an existing plugin in /Applications/Adobe Illustrator CS3/Plugins/ and "Show Package Contents" to see a plugin's contents.
* When you created the project, make sure you selected
b Carbon - Loadable Bundle
* In the Build tab of the target info dialog, make sure the
b Wrapper Extension
setting is set to
b aip
* Ensure you've got the Info.plist file set to "../common/mac/Info.plist" (or wherever this may live on your Mac)
* Ensure you've got the
b Info.plist Preprocessor Prefix File
set to "../common/includes/SDKDef.h" (or wherever it lives on your Mac)
If you're using XCode 3.0 or higher, some of the build setting names differ slightly from what is stated in the guide but they should be fairly easy to work out.