Microsoft Knowledge Base Article #935796 tells us that some applications will either experience degraded performance or not run at all after Service Pack 1 (SP1) is installed. You can find it at the link above.
This kind of thing seems to happen to one degree or another with every Windows Service Pack. To be honest, I am not sure whether to be concerned that this time so many security applications are affected or not. Right now, I think the best position to take is to simply stay informed and make plans according to how things look as we get closer to the actual release of the Service Pack.
More than anything, we need clarification of existing information and the results of more testing. I'm sure that will be done, both by Microsoft and their testers.