All of the domain objects in openstack-nova are written for v2 of the API (org.jclouds.openstack.nova.v2_0.*) but jclouds talks to v1.1 endpoints by default.
Also v1.1 hasn't been used in OpenStack since Diablo, 5 releases ago. Diablo isn't even supported anymore.
openstack-nova should default to v2 in the pom.xml test.openstack-nova.api-version and in NovaApiMetadata.
HP might still be running v1.1 on their Diablo based "pre-13.5" HPCloud which is to be discontinued on June 1, 2014.