Rob - see the video - we are talking about WTP projects not project archives. Project archives is the *last* resort to use and only relevant if you have some custom non-eclipse WTP project layout you want to publish.
Scott - if you can't drag and drop the project your project is for some reason not an Eclipse WTP project.
If you are using the AS7 quickstarts make sure you've installed the JBoss Tools Maven Integration and eclipse should be able to set this all up automatically if you use File > Import > Existing Maven projects.
So, what kind of project are you using ? And did you install Jboss Tools ? :)