PS+ will automatically download the system updates, but it won't install it, since you almost always need to agree to the new terms first ... right?
I'm going to freak out if my PS3 starts auto-updating to 4.45 tonight when I turn it on. I do indeed have a replacement HD in there. Coincidentally, "445" is my usual lottery number, on the very rare occasion that I play the Pick 3. Maybe I should pick up a ticket on my walk home.