The JackrabbitNodeTypeManager defines 3 methods that can be removed for version 2.0 since they are no longer needed:
NodeType registerNodeTypes(InputSource in) throws SAXException, RepositoryException;
NodeType registerNodeTypes(InputStream in, String contentType) throws IOException, RepositoryException;
those deal with directly register nodetypes from a XML or CND source. since we don't want to support XML serialization any longer, and the CND import can be easily done using the spi-commons CompactNodeTypeDefReader with the new JCR2.0 node type registration. if the XML is to be supported, i suggest to detach the reader similar to the CND one.
boolean hasNodeType(String name) throws RepositoryException;
this is now in the JCR2.0 api