Microsoft's Rationale for Security Updates

So I discovered a blog operated by the Microsoft Security Response Center, which is the branch of Microsoft responsible for dealing with viruses and such. The corporate vice president responsible for security posted an interesting entry that talks about the process Microsoft goes through for releasing a security update. It's very tricky, because they of course do not want to release an update that crashes lots of people's computers, so they have to move slowly but carefully.
Here' s the link to the blog.
If you use blog reading software, it is probably worth subscribing. They don't post that often, and when they do, it's usually interesting reading.