Both updates remove the most common variants of the Flashback malware, but will likely not protect users against getting infected with future variants or with any other type of malware.
In addition to the aforementioned action, the Java update for OS X Lion also configures the Java web plug-in to disable the automatic execution of Java applets.
"Users may re-enable automatic execution of Java applets using the Java Preferences application. If the Java web plug-in detects that no applets have been run for an extended period of time it will again disable Java applets," says Apple.
Snow Leopard users must disable the Java web plug-in in their web browser by themselves (Safari > Preferences > Security > deselect "Enable Java").
In the meantime, Kaspersky Lab has reissued its free Flashback removal tool after having fixed a bug that occasionally made the tool erroneously remove certain user settings including auto-start configurations, user configurations in browsers, and file sharing data.