Good news for the Linux 64-bits customers. Peoplesoft announced the 3rd of March'09 they are now certified on Linux 64-bits (OEL/RHEL), please see the metalink3 note :
Oracle PeopleSoft extends certification of OEL and RHEL 5 x86-64
The requirements for 64-bits appliance are OEL5.2 or RHEL5.2 minimum, and Peopletools 8.49.14 min.
Now, need to be tested on my lab...