Not quite: JDO (Java Data Objects) is also available for J2SE 1.4 (and below perhaps). Furthermore, JDO is not intended as a replacement for JDBC! It is simply a persistent object store framework, mainly aimed at storing business objects. It therefore cannot (and will not) replace JDBC (which is just a means to hereogenously connect to different databases).
"A chicken is an egg's way of producing more eggs."