You also have to have requirements unpacked in your eclipse as it listed on this page http://download.jboss.org/jbosstools/builds/release/3.0.0.Alpha1/ in 'Build Drivers' section on the right.
You can unpack JBoos Tools ALL-bundle in eclipse or use update site
If your using ALL-bundles, make sure you keep the eclipse structure and have all plugins in
eclipse/plugins folder and all features in eclipse/features.
it works. I installed via Eclipse Update.