Playing Unreal or Need for Speed? Then SP2 will break it.

Microsoft has published a KB for about 50 programs that seem to break once SP2 is installed.

While only a couple of them are games as I mentioned above (Midnight Outlaw anyone?) the majority are business class programs that need to be looked over before deployment into a production environment. SP2 will be coming down to a auto update enabled PC near you soon so make sure you look over this right now and see if in your environment anything will break.