Seems as though these no longer work -- at least for upversioning the jbpm plugins/features/tests in trunk, that is.
mvn org.eclipse.tycho:tycho-versions-plugin:set-version -DnewVersion=<version>
and
mvn -Dtycho.mode=maven org.eclipse.tycho:tycho-versions-plugin:set-version -DnewVersion=<version>
Thought it was related to having <version>x.y.z-SNAPSHOT</version> in pom.xml files rather than inheriting this value from parent, or that they'd changed something between 0.15.0 and 0.16.0-SNAPSHOT, but I can't for the life of me figure out why manifest.mf and feature.xml files aren't being automatically updated.