You can run Eclipse using the VM from IBM Developer Kit for AIX versions 1.3.0 or 1.3.1.  However, you MUST make sure that your AIX install has had the following APARs applied.

AIX version 4.3.3 requires APAR IY27694 (Available now)
AIX version 5.1.0 requires APAR 1Y27695 (Available in April)

IBM APARs can be downloaded from http://techsupport.services.ibm.com/server/fixes

The IBM Developer Kit for AIX can be downloaded from http://www.ibm.com/developerworks/java/jdk/aix/service.html