Hi all,
For anyone interested, I have just ported James Oden's Autorollback/Autorollback-goal RPM patches to the version of RPM present inside of CentOS 4.
The patched RPMs, SRPM and raw patches can be found online here: http://hackers.progeny.com/~sam/RPM-Autorollback/
Specifically, you can find those for CentOS 4 here: http://hackers.progeny.com/~sam/RPM-Autorollback/#wherecentos4
One of the goals of the AR/ARBG patches is to prevent failed RPM transactions from leaving a system in an unusable state. They were designed with Carrier Grade Linux in mind, but I'd wager there could be applications elsewhere.
These are the patches taken from RPM's CVS and ported into the CentOS 4 version (4.3.3).
Any questions, comments, feel free to send them to me off-list.