Well, if you haven't heard Microsoft have released Windows Server 2003 Service Pack 2. Better yet it appears as a critical update for Small Business Server. best of all, even for systems without SBS Service Pack 1 it appears as a critical update. Oh joy of joys. This is just like the fiasco when Windows Server 2003 Service Pack 1 appeared as a critical update. If was installed on your system then it would break a whole heap of things. You need to apply Windows Server 2003 Service Pack 1 as part of the Small Business Server 2003 Service Pack 1. So if your SBS system was set to automatically download and install the service pack, guess what? On the next reboot of your server you had a broken SBS.
So did Microsoft learn by this experience? Obviously not, because Windows Server 2003 Service Pack 2 is available as a critical update. Who knows what havoc it will reek on systems with Service Pack 1 already installed. It is our guess that Windows Server 2003 Service Pack 2 should work alright on SBS 2003 R2 or SBS 2003 with SBS Service Pack 1 but systems not meeting this criteria? Who knows? Problem is, someone out there is going to find out the hard way.
This is why we recommend that you don't download and automatically install Windows Updates on your server. We recommend that you set it to only notify, then you apply the updates and service packs manually.
We are in the process of test Windows Server 2003 Service Pack 2 on our internal systems and we'll provide feedback when we know more. Until then we would recommend you hang back from installing Windows Server 2003 Service Pack 2 just yet. In our books best let someone else bleed.