This has become very easy with Jackson 2.0 and the Joda module.
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JodaModule());
Maven dependency:
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-joda</artifactId>
<version>2.1.1</version>
</dependency>
Code and documentation:
https://github.com/FasterXML/jackson-datatype-joda
Binaries:
http://repo1.maven.org/maven2/com/fasterxml/jackson/datatype/jackson-datatype-joda/