You got a note from Apple? I'm impressed. I saw the same thing, some sort of mystery message when I plugged my iPhone into my Mac, a message from iTunes (which is now, of course, both the main music tool and iPhone system tool).

Here's what I saw:

As is common with Apple and, for that matter, cellphone companies, we get zero information about what is actually changed or updated.

Nonetheless, being a trusting user, I just click "Download and Update" and continue:

Just a few seconds later, it updates the phone and does the fastest sync you've ever seen (took less than a second on my 2nd gen iPhone), then:

That's it. Updated. What changed? Who the heck knows, but hopefully it will make my Apple iPhone more stable and useable.

But that's another story...