On this one, just say no.
So you have a SBS 2003 box with WSUS 3 and along the way you’ve picked up .NET 2.0.
If you are in that boat, you will find that you will get offered .NET 3.5 sp1 “and family” update to your systems.
Well sorry but .NET is one of the three patching family members that I’m not fond of at my Dinner table. The other one is a SQL 2005 sp3 service pack that I’ll also wait on. The last one I’m not keen to patch is XML as it has issues installing sometimes.
Bottom line I always patch with security patches if my risk factors that I’ve determined tell me to patch as soon as possible. However with Service Packs, I can wait. I will wait. I will test. I will hold back. And I will get my server into a condition to be Service packed. I will take a backup. I will do a system state backup. I will get to a mental happy place to deal with issues should they crop up (and with .NET getting to that mental happy place to be prepared for issues takes me a LONG time, lemme tell ya).
There is no need to install any service pack on the day, the week or perhaps even the month it comes out.
On these service packs, just say no for now and hold back.