Seems my Application class implementation was faulty and the answer
was found in the documentation:
http://jersey.java.net/nonav/documentation/1.17/jax-rs.html#d4e188
Another way to use Jackson 2.1 this seems to be to remove the
jersey-json lib from your webapp and add jackson-core and
jackson-jaxrs-json-provider (+dependencies). The latter appears to
automatically register a JSON provider.
marko