If you wonder what is the password for Oracle Internet Directory(OID) user cn=orcladmin after OIM installation, well, it is exactly the same as ias_admin password specified during installation of OIM. If you really want to reset the password, use included utility resetiASpasswd.sh in $ORACLE_HOME\bin as follows:
First make sure your environment is setup properly for OIM [...]

Oracle patchset 10.2.0.4 is now available via metalink for Windows(32bit) and Linux x86(32bit) platforms.
Update 22.05.2008: Now available also for some 64 bit platforms like AIX5L 64.