Microsoft has released a listing of applications that they have tested against Windows Server 2003 Service Pack 2. Obviously they cannot test everything so you should check with your ISV’s before deploying SP2 onto your Windows 2003 Servers, test, backup and then deploy following a change control process with a rollback plan in place. I’d recommend pilot machines being selected before you go about deploying on a widespread basis.
And a lesson learned from SP1. I haven’t checked if MS have released an SMS package definition file yet (PDF). If they have, make sure you disable the installation time limit. SP1 had a deadline that was too short for slower servers and would leave them inoperable, i.e. stop the installation half way through. I’m glad to say I found that one in a test lab.