Yesterday, the Application Compatibility Testing and Mitigation Guide for Windows XP Service Pack 2 was published.
This guide considers potential application compatibility issues that may arise after a Service Pack 2 deployment. The guide provides mitigation procedures that can be followed to overcome compatibility issues. Since the mitigation procedures relax the default security configuration, the guide in no way recommends that they should be followed, but if there is no other way of overcoming compatibility issues, they can be applied in the short term.
The Guide also includes a download of example scripts. The scripts demonstrate how to reconfigure a Service Pack 2 computer to overcome compatibility issues. The scripts are designed as functional samples and will require modification for use in a production environment.
I've only flicked though it, but I am very impressed with the level of detail of what I've seen todate.