Currently, that's still unknown. Has anyone done further testing to see if we're affected by this one?
Sun doesn't actually make the JVM or the browser plug-in used in Macs; Apple makes the JVM, and the Mozilla organization makes the plug-in for most browsers (Safari uses a different system, made by Apple). However, all of these things are based heavily on the corresponding Sun projects, and share a lot of code with them. The real question is, do they share the code with the bug?