[1. I see Nick Boldt has fixed the badly-formed feature.xml for org.jboss.tools.birt.integration.wtp.feature for JBIDE-3216]
2. org.jboss.tools.common.feature depends on org.jboss.tools.common.text.ext_feature. This feature appears not to exist, but org.jboss.tools.common.text.ext.feature does.
3. Eclipse's feature manifest editor shows a warning in the Dependencies tab for org.jboss.tools.common.text.ext.feature, because it has a hard-coded dependency on org.jboss.tools.common.core.feature 1.0.0. Changing it to greaterOrEqual seems to fix the warning.
4. org.jboss.tools.common.ui.feature and org.jboss.tools.seam.feature have dependency warnings, similar to #3
5. Several of JBT's features don't show up in JBDS's About Features. For instance, org.jboss.tools.ws.feature. It looks as if the WS plugins are being activated, but not the features. Perhaps a dependency problem like https://bugs.eclipse.org/bugs/show_bug.cgi?id=236111 ?
(I'm not sure yet, but I think problem #5 might be the reason some of my JBT langpack features refuse to install into JBDS 3.0.0.beta1.)