as reported in initial document here https://dev-platform-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/jbosstools-fuse_master/172/display/redirect?page=changes

The differences are explained in this old thread http://lists.jboss.org/pipermail/jbosstools-dev/2016-January/010908.html

I gave a talk @EclipseCon on the subject: https://www.youtube.com/watch?v=IGkFy2H-d60

To make it short:
Fuse Tooling:

• "unit test" are at class level --> plugin named *.tests, test named *Test
• "integration test" are at osgi level --> plugin named *.tests.integration, test named *IT
  Jboss Tools:
• "unit test" are at osgi level --> plugin named *.tests; test named *Test
• "integration test" are also at osgi level but with more complex requirements on environment