Windows 7 Service Pack 1 has been released. And, as with every Service Pack, issues have been reported.
The short version: make sure that you are running the latest version of any security software, including HIDS and antivirus, to make sure that it can accommodate the new version of the OS. And if you’re in a large network environment, a gradual rollout with lots of testing might not be a bad idea. This SP doesn’t actually contain anything urgent, so it’s not necessary to rush the deployment.