It turns out that you have to actually use an updater, found here, to use Cite While You Write from EndNote with Microsoft Word 2008 on a Mac.  You’ll also want to make sure you have the latest update to Word because the EndNote updater only works if Word is version 12.1.0 or higher.  Of course, you probably don’t care about this unless you’re writing your dissertation or some other referenced document but I wanted to post it so others don’t ahve to go hunting like I did.