If you plan to submit an application to the Mac App Store, please make sure you build an Intel only application. Submitting universal applications to the Mac App Store will not work. Apple rejects your application due to using private APIs.
Actually all our plugins for PPC use Apple's library glue code which uses a private API, but that was Apple's decision 10 years ago when they designed Mac OS X and someone created this glue code. But for Intel, the plugins are clean.